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Item 6b - Prado Interchange and Bridge Value Engineering
Item 6b Department: Public Works Cost Center: 5009 For Agenda of: 11/4/2025 Placement: Business Estimated Time: 90 minutes FROM: Scott Collins, Assistant City Manager Prepared By: Matt Horn, Major City Projects Manager SUBJECT: PRADO INTERCHANGE AND BRIDGE VALUE ENGINEERING RECOMMENDATION 1. Receive an update on the Prado Road Interchange Project Value Analysis phase; and, 2. Direct staff to implement the Prado Road Interchange Project Value Analysis project changes that will reduce construction costs by approximately $8,000,000; and 3. Direct staff to implement the Prado Road Interchange Project travel lane reduction cost components that will reduce construction costs by approximately $12,000,000; and 4. Direct staff to implement a shared use path along the south side of Prado Road through the Prado Road Interchange Project and to Higuera Street. REPORT-IN-BRIEF The Prado Road Interchange Project (Interchange Project) is a long-planned regional mobility improvement that will extend Prado Road over US 101 to Dalidio Drive, realign Elks Lane, and add a northbound auxiliary lane to Madonna Road. Together with the adjacent Prado Creek Bridge Replacement Project (Bridge Project) and future Prado Road Extension Project (Road Extension Project), will complete a critical multimodal east–west connection across the City, improving congestion, safety, and access for all travel modes. In 2023, the City Council approved the Preferred Alternative (Attachment A) for the Interchange Project and awarded the Plans, Specifications, and Estimate (PS&E) design phase to Consor Engineering in February 2025. During the discussion on the design phase contract with Consor, Council expressed concern over escalating project costs, now estimated at $147 million, with roughly $110 million still unfunded, and directed staff to pursue additional cost-reduction strategies and regional funding opportunities. Consor Engineering’s Value Analysis work determined that several refinements to the Interchange Project are feasible that collectively reduce estimated construction costs by about $8 million while maintaining multimodal functionality. These include using cast-in- drilled-hole (CIDH) columns instead of driven piles, long-span precast girders to avoid falsework over US 101, reducing bridge design speed and deck width, and increasing use of recycled materials. Further evaluation of traffic lane width reductions and traffic lane Page 199 of 349 Item 6b reductions and a consolidated shared-use path on the south side of Prado Road could yield an additional $12 million in savings (Attachment B). To implement these refinements, Consor divided Prado Road into three segments, tailoring cross-sections to context. The segments are visual shown in this report in Figure 7 and described below: Segment 1 connects to the San Luis Ranch area at Dalidio Drive and goes over US 101 and ends at the US 101 northbound on and off ramps. This segment is planned to reduce the overpass width from over 103 feet to 63 feet; Segment 2 connects to Segment 1 at the US 101 northbound on and off ramps and ends at the new location of the Elks at Prado Road intersection. This segment widens to 85 feet to accommodate the northbound on and off ramps for US 101; and Segment 3 connects to Segment 2 at the new location of the Elks at Prado Road intersection. This segment transitions Prado Road and its multimodal design to the upcoming Bridge Project improvements. Extending the proposed shared-use- path design through the Bridge Project and to Higuera Street could reduce costs for the Bridge Project and provide corridor-wide consistency. Staff, in coordination with San Luis Obispo Council of Governments (SLOCOG), Caltrans, and Consor, are preparing the project for competitive grant cycles such as the Federal Rebuilding American Infrastructure with Sustainability and Equity (RAISE) and State SB 1 Solutions for Congested Corridors (SCCP) programs and exploring “bundling” the Interchange Project with adjacent corridor projects to improve funding competitiveness. The Active Transportation Committee (ATC) reviewed this item on October 23, 2025, and that input is included with this report. Staff is seeking direction from Council on whether to implement: The Value Analysis recommendation to reduce cost of the Interchange Project by approximately $8,000,000; and The travel lane reductions to reduce the costs of the Interchange Project by approximately $12,000,000; and The proposed shared use path on the southerly side of Prado Road until Higuera that could reduce construction cost of the Bridge Project. Staff is recommending this project alternative, which is referred to later within this report as the Preferred Alternative Value Analysis with Lane Reduction (PA VA + Lane Reduction). POLICY CONTEXT The Interchange Project and the Bridge Project support the Major City Goals for Infrastructure and Sustainable Transportation. The Land Use and Circulation Element (LUCE) of the General Plan and the 2021 Active Transportation Plan identifies a lack of multi-modal east-west connections across the City, which these projects propose to construct. Page 200 of 349 Item 6b Additionally, the General Plan also identifies the Interchange Project as essential in facilitating recent and future growth in the southern portion of the city. Many of the trips generated from existing uses, as well as proposed and previously approved development projects will use the Interchange Project as a primary east-west link. Approved environmental documents for numerous private housing development pr ojects in this area of the city, including San Luis Ranch, Avila Ranch, Froom Ranch Specific Plan, and the Margarita Area Specific Plan, identify construction of the Interchange Project as essential infrastructure necessary to address current and future tr affic congestion and circulation deficiencies. Funding for the Interchange Project has been significantly supported through contributions required under the San Luis Ranch Development Agreement (DA). As part of the DA, San Luis Ranch was obligated to provide bond proceeds to the City specifically for the Interchange Project. The Prado Interchange is identified as a reimbursable facility within the City’s Transportation Impact Fee (TIF) Program, which collects proportional contributions from new development to fund transportation infrastructure. DISCUSSION Background The Interchange Project is a long-planned regional mobility improvement that will extend Prado Road over US 101 to Dalidio Drive, realign Elks Lane, and add a northbound auxiliary lane to Madonna Road. Together, these improvements will relieve congestion, strengthen multimodal connectivity, and improve emergency access across the southern portion of the City. On September 5, 2023, the City Council reviewed several different alternatives for the Interchange Project and selected the Preferred Alternative and approved the Project Report. The total current and future cost to implement the Preferred Alternative is anticipated to be $147 million of which $110 million has yet to be secured and is anticipated to be funded by both grants and debt financing. On February 18, 2025, the City Council awarded the Plans, Specifications & Estimate phase of the project to Consor Engineering and expressed significant concern regarding the total cost of the project, the anticipated amount of debt financing the City would be required to take on, and expressed a strong desire to obtain additional regional funding for the project. At that same time, the City Council approved of the planned value analysis work to identify potential project cost savings through alternative designs. Project Background The Interchange Project has been identified in City and Regional Transportation Plans to address east–west connectivity constraints created by the US 101 and how the City has developed around the US 101. Current crossings at Los Osos Valley Road (LOVR) and Madonna Road are at capacity, and regional growth is projected to degrade operations on both US 101 and local streets. Completed housing projects, such as San Luis Ranch and future planned housing development in the Margarita Area and adjacent to Tank Farm Road are dependent upon completion of this project. Page 201 of 349 Item 6b Both the Preferred Alternative and the Value Analysis alternative for the Prado Interchange Project will: Extend Prado Road over US 101 to Dalidio Drive, creating a continuous east–west arterial connection. Reconstruct the northbound on/off -ramps and add a northbound auxiliary lane between Prado and Madonna. Realign Elks Lane behind the RTA facility and 40 Prado Homeless Services Center to connect with Prado Road at a new signalized intersection. Widen Prado Road between Elks Lane and South Higuera Street with sidewalks and bikeways. These improvements will reduce citywide vehicle miles traveled (VMT) by approximately 0.5% (≈ 2,700 miles per day), relieve congestion at neighboring interchanges, and complete a critical multimodal corridor identified as a Tier 1 priority in the 2021 Active Transportation Plan. Figure 1 – Plan View of the Preferred Alternative Figure 2 – Interchange Renderings (US 101 Northbound) Figure 3 – Interchange Renderings (US 101 Southbound) Page 202 of 349 Item 6b Related Projects – Prado Corridor Connectivity Projects The Interchange Project is one of three coordinated projects that together will create a critical east–west connection linking Broad Street to Madonna Road. This continuous multimodal corridor will provide improved access for vehicles, bicycles, pedestrians, and transit, relieving congestion on existing interchanges and enhancing connectivity between key employment, residential, and commercial areas in the southern portion of the City. The three related projects are shown below in Figure 4 and include: Bridge Project Located west of South Higuera Street, this separate bridge replacement is required due to structural deficiencies of the bridge and will proceed before the Interchange Project. This project will reconstruct the Prado Road and Higuera Street intersection, replace the existing Prado Road Bridge at San Luis Creek, improve Prado Road from Higuera Street westerly to the beginning of the City’s Water Resource Recovery Facility, and provide bicycle facilities on Prado Road east of Higuera Street to the Serra Meadows Roundabout. Coordination between both projects is ongoing to ensure design consistency and minimize disruption. Road Extension Project The City has a long-range plan to extend Prado Road east to Broad Street to complete the corridor connecting Broad to Madonna. Timing of this future project will depend on private development participation and right-of-way dedication. It is the intent of both the Interchange Project and the Bridge Project to size and construct the planned improvements to facilitate a future connection to Broad Street. Figure 4 – Related Project Vicinity Map Page 203 of 349 Item 6b Interchange Project Delivery Process – Caltrans Delivery Process The Interchange Project is a partnership between the City and Caltrans. Caltrans is assisting the City with project delivery and will eventually assume maintenance of portions of this facility (as Caltrans current does with the LOVR and Madonna Road interchanges). Throughout the process (from planning to construction), Caltrans staff review and approve major deliverables to ensure compliance with Caltrans standards. Once the Interchange Project is constructed, Caltrans will assume maintenance for the bridge structure, ramps, and operation of the Prado Road/US 101 Northbound Ramps traffic signal. All improvements within Caltrans Right-of-Way must be designed to Caltrans Standards. The Caltrans interchange delivery process is divided into four phases which are as follows: 1. Project Study Report – Project Development Support (PSR-PDS): This is the project initiation phase which outlines the transportation problem and potential solutions. This phase for the Interchange Project was completed in 2018. 2. Project Approval & Environmental Document (PA/ED): This phase of work develops several alternatives, completes the necessary environmental review and clearance, and upon completion the selection of the Preferred Alternative for further design in the next phase. Due to the anticipated project cost, a value analysis was completed in order to reduce costs where appropriate. The PAED phase of work was completed in 2024. 3. Plans, Specifications & Estimate (PS&E): This phase of work will complete the value analysis work that was started in the PAED phase and complete the plan s for the Interchange Project to a state in which the City will be able to publicly bid the project for a contractor to construct the Interchange Project. This is the current phase of the project which is anticipated to be complete in 2029. 4. Construction: This phase of work will construct the design improvements. Construction is anticipated to start in 2029 dependant upon project funding. Value Analysis and Alternatives to Reduce Project Cost A formal five-day Value Analysis workshop was completed in March 2023. Through this process, staff and consultants evaluated opportunities to reduce project costs and improve constructability while maintaining multimodal goals. Recommendations from this work included: 1. Use cast-in-drilled-hole columns instead of driven piles. 2. Use long-span precast girders to increase the speed of construction. 3. Reduce the bridge design speed from 45 mph to 35 mph , which will reduce structure size and cost. 4. Reduce lane and shoulder widths to reduce deck area. 5. Increase recycled content (aggregate, steel, fly ash) in the concrete design to lower cost and emissions. Page 204 of 349 Item 6b Both City and Caltrans staff agreed that these recommendations warranted additional analysis and decided to conduct that evaluation as one of the first tasks in the next phase of the project (PS&E phase). This information was included in the staff report that was presented to Council on September 5, 2023. On September 5, 2023, City Council reviewed several different alternatives for the Prado Interchange Project and selected the Preferred Alternative. The Preferred Alternative for the Interchange Project is shown in Figure 1 of this report and includes the following improvements: Tight-diamond partial interchange with northbound ramps. Two travel lanes each direction on Prado Road with median/turn lane. Protected sidewalks and bikeways on both sides of the bridge. Elevated roadway segments supported by columns to avoid floodplain impacts. Elks Lane realignment and new signalized intersection. Space reserved for potential future southbound ramps. Since that time, however, the costs for construction of th e project have escalated by approximately $34.2 million. The total current and future cost to implement the Preferred Alternative is anticipated to be $147 million of which $110 million has yet to be secured and is anticipated to be funded by both grants a nd debt financing. On February 18, 2025, City Council awarded the Plans, Specifications & Estimate (PS & E) phase of the project to Consor Engineering and expressed concern regarding the total cost of the project and approved the planned value analysis work to fully evaluate the possible cost reductions from the potential design changes identified in the above referenced March 2023 value analysis workshop. Given this concern, Consor Engineering’s first action was to evaluate how these cost reduction-strategies could be integrated into the final design for Council’s consideration. Consor Engineering’s Value Analysis Work Following award of the PS&E contract, Consor Engineering evaluated the 2023 value analysis recommendations to confirm which recommendations could be integrated into final design to improve constructability, reduce cost, and maintain multimodal functionality consistent with Caltrans standards and the City’s design objectives. Consor Engineering’s review confirmed that the following key recommendations from the 2023 workshop are technically sound and should be incorporated into the project: 1. Cast-in-Drilled-Hole (CIDH) Columns: Replacing driven piles with large-diameter CIDH shafts reduces construction noise, minimizes vibration impacts to nearby facilities such as 40 Prado and the Regional Transit Authority (RTA) campus, and reduces the need for large underground pile caps. This approach also shortens construction time and simplifies foundation work within constrained utility and floodplain areas. 2. Long-Span Precast Bridge Girders: Utilizing longer precast girders eliminates the need for falsework over U.S. 101, which reduces traffic impacts, improves safety, and lowers required bridge elevation. The reduced profile shortens overall bridge length and results in substantial material and cost savings. Page 205 of 349 Item 6b 3. Reduced Design Speed and Roadway Width: Lowering the bridge design speed from 45 to 35 miles per hour allows for tighter horizontal and vertical geometry and, in combination with slightly narrower lane and shoulder widths, reduces the bridge deck area. This smaller footprint supports the City’s target spe ed objectives and lowers construction and right-of-way costs while maintaining acceptable traffic operations. 4. Increased Use of Recycled and Reclaimed Materials: The design will maximize the reuse of existing pavement and base materials from Elks Lane, Prado Road, and the freeway ramps. These materials can be incorporated into new asphalt and concrete, reducing greenhouse gas emissions and material costs. The combination of these refinements is estimated to reduce total project construction costs by approximately $8 million. In addition to cost savings, these changes provide environmental and community benefits by reducing noise, lowering construction duration, and maintaining access for nearby facilities. The same value analysis also highlighted that traffic lane and shoulder widths could be reduced to further reduce project costs. In addition to these reductions , Consor Engineering looked at the context of the corridor. The project is essentially abutting two existing but separate shared use bike and pedestrian paths that are not currently planned to be connected. See Figure 5 below: Figure 5 – Location of San Luis Ranch and Bob Jones path terminuses Page 206 of 349 Item 6b Consor Engineering is recommending implementation of the traffic lane width reductions identified in the 2023 Value Analysis to reduce overall construction costs while maintaining multimodal connectivity. In addition, Consor Engineering proposes consolidating bicycle and pedestrian facilities into a single shared -use path along the southerly side of Prado Road, rather than providing separate on -street striped bike lanes and sidewalk-level one-way protected bike lanes on both sides of Prado Road. This approach reduces the total bridge width and is anticipated to reduce project costs by approximately $12 million while still meeting the City’s multimodal objectives (in addition to the other $8 million in cost savings identified by Consor). Consor Engineering’s design philosophy emphasizes providing on-street bicycle facilities for strong and confident riders, while also incorporating a protected shared-use path on one side of the street for users who prefer greater separation from vehicle traffic. These proposed modifications are discussed in the next section. Consor Engineering’s Value Analysis Lane Reductions Along Prado Road, the Preferred Alternative design provides two travel lanes in each direction, a center lane used for turning movements or median, and paved shoulders on both sides of the roadway. The design also includes one -way sidewalk-level protected bicycle lanes and sidewalks on both sides to accommodate multimodal travel. To support this cross section, the bridge portion of the project spanning US 101 would have to be constructed with a width exceeding 103 feet. Based on cu rrent market conditions, each additional foot of bridge width adds approximately $500,000 to the total construction cost. Figure 6 below illustrates a typical cross section of the Preferred Alternative proposed roadway. Figure 6 – Typical Roadway Section for the Preferred Alternative along Prado Road Given the significant cost associated with bridge construction, Consor Engineering focused on strategies to reduce the overall bridge width while still meeting the project’s transportation and multimodal goals. To achieve this, the design team divided Prado Road into three functional segments, as illustrated in Figure 7. Page 207 of 349 Item 6b Segment 1 connects to the San Luis Ranch area at Dalidio Drive and goes over US 101 and ends at the US 101 northbound on and off ramps. This segment is planned to reduce the overpass width from over 103 feet to 63 feet; Segment 2 connects to Segment 1 at the US 101 northbound on and off ramps and ends at the new location of the Elks at Prado Road intersection. This segment widens to 85 feet to accommodate the northbound on and off ramps for US 101; and Segment 3 connects to Segment 2 at the new location of the Elks at Prado Road intersection. This segment transitions Prado Road and its multimodal design to the upcoming Bridge Project improvements. Extending the shared-use-path design through Bridge Project and to Higuera Street could further reduce costs on the Bridge Project and provide corridor-wide consistency. By separating the roadway into these segments, Consor was able to tailor the cross section and structural design for each segment—narrowing travel lanes, adjusting median widths, and varying structural support types where appropriate—to minimize bridge width and associated construction costs while maintaining safety, acc ess, and multimodal continuity across the corridor. Figure 7 – Prado Road Segments Segment 1 value engineering reduces the overpass bridge width from more than 103 feet down to approximately 63 feet by providing a more efficient cross section consistin g of one vehicle travel lane in each direction, a center lane used for turning movements or as a median and space for emergency vehicles to bypass traffic, on-street bike lanes, a sidewalk on the north side of the bridge, and a shared -use path on the south side. This configuration maintains multimodal access while significantly reducing bridge width and overall Interchange Project construction cost. Page 208 of 349 Item 6b Figure 8 – Segment 1 – Limits Completely with Interchange Project Segment 2 widens the bridge from approximately 63 feet in Segment 1 to about 85 feet to accommodate the northbound on- and off-ramps connecting Prado Road to US 101. Although this represents an increase over Segment 1, it remains approximately 18 feet narrower than the bridge width included in the Preferred Alternative. The added width provides two additional travel lanes to improve ramp operations and traffic flow through the interchange area. This segment also extends the shared -use path along the south side of Prado Road and includes two travel lanes in each direction with a center turn lane or median. The configuration enhances safety and accessibility for all users while providing direct access to the realigned Elks Lane and the City’s Water Resource Recovery Facility (WRRF). Figure 9 – Segment 2 - Limits Completely with Interchange Project Segment 3 provides the transition between the Segment 2 improvements and the planned Bridge Project improvements. Approximately half of this segment is included in the Interchange Project and the other half in the Bridge Project. The design includes two travel lanes in each direction, a center turn lane or median, a sidewalk and protected bike path on the north side of the roadway, and a shared -use path on the south side. This segment connects to the future improvements at the Prado Road/South Higuera Street intersection and advances the City’s long-term goal of creating a continuous east–west multimodal corridor from Broad Street to Madonna Road. Page 209 of 349 Item 6b Figure 10 – Segment 3 – Shared Improvements between Interchange & Bridge projects Bridge Project Value Engineering Figures 11 and 12 below illustrate the planned improvements for the Bridge Project. This project is currently designed to provide six travel lanes, on -street shoulders/bike lanes, one-way sidewalk-level protected bike lanes on each side of the street, sidewalks, for the intersection of Prado and Higuera, and includes relocation of the existing Bob Jones Trail bridge to accommodate the widened roadway. The current estimated cost of the Bridge Project is approximately $45.5 million. Figure 11 – Plan View of Bridge Project Page 210 of 349 Item 6b Figure 12 – Prado Road Section for the Bridge Project If the previously discussed bicycle and pedestrian configuration from Segments 1 and 2 featuring a shared-use path on the south side and consolidated multimodal facilities were extended through the Bridge Project, there is an opportunity to achieve consistency across the corridor and may reduce overall costs for this project. Additionally, with this change there may be more opportunities to reduce costs of this Bridge Project by connecting to the existing Bob Jones Trail and n egating the need to remove and replace the existing bridge that services this trail exclusively. The re also could be other cost saving opportunities if Council wishes to proceed with a value analysis for Bridge Project. Safety of Shared Use Paths Shared-use paths provide complete separation between bicyclists, pedestrians, and motor vehicles, greatly reducing exposure to serious conflicts. The City of San Luis Obispo designs these facilities in accordance with both Caltrans and National Association of City Transportation Officials (NACTO) standards. National research shows that shared- use paths reduce bicycle crash rates compared to on-street conditions (FHWA, 2019). These design and operational practices make shared-use paths among the safest and most comfortable multimodal facilities for users of all ages and abilities. Beyond safety, maintaining a consistent shared-use path along Prado Road, matching the adjacent facilities on Madonna Road and Froom Ranch Way, simplifies navigation for users, reduces potential conflict points at the Elks Lane and northbound on-ramp intersections, and lowers costs by minimizing roadway width and streamlining intersection design and operations. Cost Comparison Table 1 presents a comparison of Interchange Project costs by phase. The column labeled PA represents the cost of implementing the Preferred Alternative selected by City Council in 2023. The column labeled PA VA reflects the same Preferred Alternative that incorporates the Value Analysis recommendations (use of cast-in-drilled-hole columns, long-span precast girders, reduced bridge design speed, and increased use of recycled materials). The column labeled PA + Lane Reduction includes the Value Analysis recommendations and additional cost savings associated with narrower travel lane and lane reductions (which is staff’s recommended alternative). It is assumed that costs for other project phases, including design, right of way acquisition, utility relocation, construction administration, and construction management, will remain largely unchanged regardless of which construction cost reductions are implemented. Because a large portion of the project cost is anticipated to be debt financed, the table Page 211 of 349 Item 6b also identifies the corresponding annual debt service savings that would be realized over a 30-year repayment period under each reduced cost alternative. Table 1 – Cost Comparison Phase PA PA VA PA VA + Lane Reduction Design $10,045,780 $10,045,780 $10,045,780 Right of Way $2,000,000 $2,000,000 $2,000,000 Utilities Relocation $2,000,000 $2,000,000 $2,000,000 Construction Admin $2,000,000 $2,000,000 $2,000,000 Construction Management $11,000,000 $11,000,000 $11,000,000 Construction $119,000,000 $111,000,000 $99,000,000 Project Total1 $147,545,780 $139,545,780 $127,545,780 Annual Debt Payment Savings (for 30 years)2 - $490,664 $1,222,660 Debt service payments for projects included in the City’s Capital Improvement Plan are funded through future allocations from the 10-Year Capital Improvement Plan budget. As a result, any reduction in the total project cost directly increases the City’s future capacity to deliver other capital improvements. Conversely, higher project costs would reduce the amount of funding available over the next 30 years for other public improvements such as roadway rehabilitation, sidewalk replacement, ADA improvements, park development, large City facility construction such as a new Public Safety Center, City fleet purchases, and active transportation projects. Future Grant Possibilities Staff, in coordination with SLOCOG and Consor Engineering, are actively monitoring several federal and state funding programs that align with the Interchange Project. The most competitive opportunities are anticipated to include the Federal Rebuilding American Infrastructure with Sustainability and Equity (RAISE) program and the State SB 1 Solutions for Congested Corridors (SCCP) program, both of which prioritize multimodal connectivity, safety, and climate-resilient infrastructure. In addition, there may be opportunities to enhance overall grant competitiveness by bundling the Interchange Project with complementary corridor improvements, such as the Bridge Project and future active transportation connections. This bundling approach has been successfully utilized within the region to secure SB 1 funds for the US 101 South County Mobility Improvement Project. Lastly, the City is also exploring the Affordable Housing and Sustainable Communities (AHSC) potential grant opportunity with Community Action Partnership of San Luis Obispo County (CAPSLO) to fund supportive housing and transportation needs that could fund a portion of this project. 1 Inflationary cost is estimated to be 5% per year and matches what was presented to Council on February 18, 2025. 2 Debt service savings assumes the interest rate of funds received is 4.6% which is consistent with the debt service calculation presented in the 2025-27 Financial Plan. Any project savings realized through value analysis work was assumed to reduce the amount of funding borrowed. Page 212 of 349 Item 6b Staff will continue coordination with SLOCOG, Caltrans, CAPSLO and Consor to position the project for upcoming funding cycles and to maximize external grant cont ributions, thereby reducing the City’s future debt obligations associated with the Interchange Project construction. Consistency with the Active Transportation Plan The City’s Active Transportation Plan (ATP), adopted by City Council on February 2, 2021, is a 20-year blueprint to make walking, bicycling, and other human-powered travel safe, connected, and accessible for people of all ages and abilities. Replacing the 2013 Bicycle Transportation Plan, it supports the City’s Climate Action Plan and General Plan Circulation Element goals to reduce vehicle use and carbon emissions. The ATP includes a prioritized network of new and improved bikeways, sidewalks, and crossings; design guidelines aligned with state and national best practices; and programs to encourage and educate residents about active travel. In the vicinity of US 101, the ATP’s Figure 18 on Page 99 proposes bike and pedestrian improvements shown in Table 2 below. Table 2 – Related ATP Areas Roadway ATP Identified Improvements Prado Road Protected Bike Lanes Los Osos Valley Road Protected Bike Lanes Madonna Road Shared Use Path & Protected Bike Lanes California Shared Use Path Ultimately, the tangible changes from an active transportation perspective proposed with the Value Analysis (VA) + Lane Reduction Alternative are relatively limited but meaningful. The changes include: 1. Eliminating a one-way protected bike lane on the north side of Prado Road for a portion of the corridor, 2. Consolidating pedestrian and bicycle facilities on the south side of the street as a shared-use path, and 3. Allowing two-way bicycle travel on the south side of the street. Pros: The proposed modification would lower overall project cost, improving the likelihood that the interchange can be built. It would also create a more intuitive and convenient two - way bicycle connection between the San Luis Ranch shared-use paths and the Bob Jones Trail, reducing the likelihood of wrong-way cycling behavior. Cons: Pedestrians would need to share space with bicycles along the south side of the corridor, which can increase potential conflicts at intersections and driveways compared to the previously proposed one-way bikeway configuration. Page 213 of 349 Item 6b Impacts to Vehicle Travel from Lane Reduction The consultant team prepared a Traffic Sensitivity Analysis (Attachment C) to compare traffic operations and emissions for the Interchange Project’s design alternatives. The purpose of the analysis was to ensure that the City, Caltrans, and the community could compare whether the four-lane Preferred Alternative provides operational benefits that justify its higher cost relative to the two-lane Value Analysis alternative. The analysis determined that both the four-lane and two-lane configurations would operate at Level of Service (LOS) D or better at all intersections, indicating comparable overall performance. Average vehicle delay for the two-lane alternatives was only one to three seconds higher, well within acceptable LOS D thresholds, and queueing was generally contained within available storage for both options. Under the two -lane configuration, westbound queues may approach Elks Lane due to signa l control, though this could be mitigated through a free-flow turn movement. Greenhouse gas (GHG) emissions modeling found slightly lower peak-hour CO₂ emissions for the two-lane alternatives (approximately 19.9 –20.7 tons) compared to the four-lane design (20.2–21.3 tons), with the narrower two-lane configuration producing a smaller carbon footprint due to reduced idling and shorter travel distances. Overall, the four-lane alternative offers only marginal operational advantages at a significantly higher cost. The two-lane alternative achieves equivalent LOS, lowers GHG emissions, maintains multimodal connectivity, and minimizes construction and environmental impacts. Next Steps Following Council direction, the consultant team will prepare a Supplemental Project Report (SPR) for Caltrans review and approval. All value analysis modifications located within Caltrans right-of-way will require formal Caltrans approval through this SPR process. City and Caltrans staff continue to work collaboratively on the pro ject and remain supportive of implementing cost-saving measures identified through the value analysis process. If the Council’s selected direction differs from the improvements identified in the City’s adopted Active Transportation Plan (ATP), staff will return to Council with a resolution amending the ATP to ensure consistency with the updated project scope along Prado Road. The Council’s next anticipated action on this project will be to review and approve the Supplemental Project Report, following Caltrans’ review, in early 2026. Construction is currently projected to begin in 2029. Prior to that time, Council will consider several related actions, including Bridge Type Selection, grant applications, right -of-way acquisitions, maintenance agreements with Caltrans, and authorization to advertise the Interchange Project for construction bids. Page 214 of 349 Item 6b Active Transportation Committee Feeback On October 23, 2025, the Active Transportation Committee (ATC) reviewed this item. The ATC was specifically asked to provide input on: A. Does the proposed Value Analysis Alternative provide the appropriate level of service for bicycle and pedestrian travel? B. Should the same multimodal design standard be extended east to South Higuera Street and integrated into the Prado Creek Project to ensure corridor continuity and reduce project costs? By unanimous vote of all members present, the ATC provided the following recommendations: 1. ATC supports an elevated shared use path on south side of Prado through entire length of project. 2. ATC supports a one-way bike lane on each side of the roadway throughout the entire length of the project. 3. ATC supports the use of Class 4 bike lanes throughout the project. 4. ATC supports the value analysis alternative with the added additions of the previous motions. Based on the ATC’s input, Consor Engineering developed updated cross sections and preliminary cost estimates for the proposed design refinements. Figure 13 below illustrates the ATC’s preferred configuration, which includes protected one-way bike lanes on both sides of the roadway while maintaining a shared-use path on the south side of Prado Road. Implementing this configuration across the Interchange Project segments is estimated to increase total project costs by approximately $4 million and may require additional right-of-way acquisition along Prado Road at an additional cost to the overall project (more information to be presented to City Council a t the November 4, 2025 City Council meeting). Figure 13 – Protected one-way bike lanes and shared-use path Page 215 of 349 Item 6b Figure 14 illustrates an alternate configuration preferred by some ATC members, which includes protected one-way bike lanes on both sides of the roadway but removes the shared-use path on the south side. Implementing this configuration is not anticipated to increase or decrease total project costs. Figure 14 – Protected one-way bike lanes and sidewalks – no shared-use path It should be noted that ATC’s recommendations were noted by staff but the formal approved minutes of this meeting will not be available until November 20, 2025. Previous Council or Advisory Body Action Interchange Project The Interchange Project is included in the City’s 1992 Circulation Element of the City’s General Plan. On July 17, 2018, City Council approved the Supplemental Environmental Impact Report (SEIR) for the San Luis Ranch Development (Staff Report, Minutes). The SEIR detailed the impacts of the development and need for the Interchange Project, but did not cover the project itself, necessitating separate CEQA and NEPA documents. The Active Transportation Plan was adopted by Council on February 2, 2021. On August 16, 2022, Council Authorized Staff to seek VA services and PS&E services (Staff Report, Minutes). On September 5, 2023, Council recommended approval of the Initial Study – Mitigated Negative Declaration (IS-MND) to Caltrans, declared Alt 3 as the City’s preferred interchange type, and recommended that Caltrans Administration approve the Project Report. (Staff Report, Minutes) Page 216 of 349 Item 6b On February 18, 2025, Council awarded the PS&E design contract to Consor Engineering (Staff Report, Minutes). On October 23, 2025, the Active Transportation Committee reviewed this item and the results of that meeting are included in above. Bridge Project On August 20, 2013, Council authorized the advertisement an RFP for advanced technical studies for the Bridge Project. (Staff Report, Minutes) On October 21, 2014, Council reviewed several bridge types and selected the bridge type to replace the existing Prado Creek Bridge. (Staff Report, Minutes) On October 4, 2022, and October 18, 2022, an undergrounding ordinance was introduced, and a second reading of that ordinance occurred to place existing overhead utilities underground in connection with the project. (Staff Report, Minutes, Staff Report, Minutes) Public Engagement Interchange Project There were extensive opportunities for public engagement on the project through previous planning efforts, including the 2014 General Plan Land Use and Circulation Element (LUCE) update, during review of the San Luis Ranch development proposal and Environmental Impact Report, approved in 2018, and through public input on the City’s capital project prioritization during the past several budget cycles. On February 15, 2023, a focused workshop was held to solicit input on the latest Interchange Project’s details and draft environmental document. This meeting included a presentation on project background, overview of design alternatives considered, discussion of traffic impacts, summary of environmental analysis and mitigation recommendations, latest project cost estimates and schedule. The meeting was advertised via legal ads, via City email and social media notifications, and via direct mailers sent to businesses and residents located within one half mile of the project limits. Caltrans representatives were in attendance to help field questions from the public. The IS/MND was circulated for public review February 2 through March 6, 2023. The Notice of Availability/Notice of Intent to Adopt the IS/MND was advertised in the local newspaper and included information about and invitation to the February 15, 2023 public meeting. Following the public review period, Caltrans and City staff recorded and jointly responded to 10 comment letters from members of the public and 1 from a local agency. These responses have been reviewed by staff and approved by Caltrans and are included at the end of the IS-MND. Bridge Project A public meeting was held at the City’s Corporation Yard (25 Prado, San Luis Obispo) on July 26, 2022. Prior to the public meeting, postcards we re distributed to affected property owners inviting the public to the meeting. No comments or concerns were received. Page 217 of 349 Item 6b CONCURRENCE The Fire Department expressed support for the Interchange Project and the proposed Value Analysis modifications, emphasizing that improved east–west connectivity will significantly enhance emergency access to the southern portion of the City. The new overcrossing will improve response capability from Station 4 and help the department move closer to achieving its four-minute travel time goal identified in the City’s Climate Adaptation and Safety Element. Current response times have declined in recent years due to increasing call volumes and continued growth in the southern area of the City; therefore, the Prado overpass is anticipated to enhance emergency response, strengthen the Effective Firefighting Force (EFF) through faster multi-unit arrivals, and improve overall safety for pedestrians and cyclists. The Fire Department also expressed support for the proposed shared -use path on the south side of Prado Road connecting the Bob Jones Trail to San Luis Ranch, noting that this linkage could reduce the need for other types of protected bicycle facilities that may otherwise impact emergency response times. The Police Department expressed support for the proposed modifications as well, recognizing the immediate benefit of an additional crossing over U.S. 101 while noting potential long-term concerns regarding vehicle capacity over the life of the project. The Department considers the reduced design speed acceptable given the improved east– west connectivity and supports the proposed shared -use path on the south side of Prado Road. Both departments emphasized the importance of maintaining emergency-vehicle signal preemption throughout the project area and at adjacent intersections to ensure efficient emergency response, particularly where only a single through lane is provided. ENVIRONMENTAL REVIEW Both the Interchange Project and Bridge Project have completed and approved environmental documents in compliance with the California Environmental Quality Act (CEQA) and the National Environmental Policy Act (NEPA). Under CEQA, the City of San Luis Obispo served as the lead agency and prepared Initial Study/Mitigated Negative Declarations (IS/MNDs) for both projects. Under NEPA, Caltrans served as the lead agency and determined that both projects qualified for Categorical Exclusions. For the Bridge Project, Council approved the IS/MND on October 4, 2022 by Resolution Number 11368 (2022). Caltrans approved the NEPA document on January 11, 2023. For the Interchange Project, Council approved the IS/MND on September 5, 2023 by Resolution Number 11447 (2023). Caltrans approved the NEPA document on October 8, 2024. Page 218 of 349 Item 6b FISCAL IMPACT Budgeted: Yes Budget Year: 2025-30 Funding Identified: Yes Table 3 – Standard Financial Table Funding Sources Total Budget Available Current Funding Request Remaining Balance Annual Ongoing Cost General Fund $ 0 $ 0 $ 0 $ 0 State $ 0 $ 0 $ 0 $ 0 Federal $ 0 $ 0 $ 0 $ 0 Total $ 0 $ 0 $ 0 $ 0 Fiscal Analysis: Both the Interchange Project and the Bridge Project are included in the City’s 2025-27 Financial Plan. The Interchange Project appears on page 384 of the plan. The Bridge Project appears on page 379 of the plan. Below is a breakdown of both projects anticipated costs and funding plan. Interchange Project Table 4 –Interchange Project’s Anticipated Costs (Current Preferred Alternative) Phase Current 2027-28 2028-29 2029-30 Design $11,545,780 Phase1 $3,049,853 Phase 2 $5,901,488 Phase 3 $94,439 Contingencies $1,000,000 Third Party Review $1,500,000 Right of Way $2,000,000 Utilities Relocation $2,000,000 Construction Admin $2,000,000 Construction Management $11,000,000 Contract $10,000,000 Contingency $1,000,000 Construction $119,000,000 Contract $99,166,667 Contingency $19,833,333 Total $11,545,780 $2,000,000 $2,000,000 $132,000,000 Grand Total $147,545,780 Page 219 of 349 Item 6b Table 5 –Interchange Project’s Funding Plan from the 2025-27 Financial Plan Funding Source Current 2027-28 2028-29 2029-30 Local Funds: $15,261 $75,000,000 Capital Outlay (LRM) $15,261 Debt Finance $75,000,000 Regional Funds: $1,435,260 Regional Grant (County) $1,435,260 Developer Funds: $10,483,063 $2,000,000 $2,000,000 $11,000,000 Capital Outlay (SLR) $9,967,681 $2,000,000 $2,000,000 $11,000,000 Airport Area Impact Fee $79,205 Transportation Impact Fee $436,177 Grants: $35,000,000 Grant (SLOCOG) $10,000,000 Grant (Future) $25,000,000 Total $11,933,584 $2,000,000 $2,000,000 $121,000,000 Grand Total $136,933,584 Securing debt financing for the Interchange Project would likely require the City to pledge City-owned properties as collateral. However, most of the City’s high -value assets are already pledged to existing debt issuances, limiting the availability of unencumbered properties. Preliminary estimates indicate the City could assemble enough collateral to support a bond of up to approximately $75 million, though this would likely require leveraging a broad portfolio of properties. To better define available collateral and overall bonding capacity, staff will begin obtaining broker opinions of value for key City facilities. In addition, the City has retained Kosmont Companies, a financial advisory firm, to evaluate alternative funding strategies and financing instruments for the project. It should be noted that the anticipated project costs shown in Table 4 exceed the current funding plan presented in Table 5. The funding plan in Table 5 was developed as part of the 2025–27 Financial Plan and assumes that Council would implement some portion of the Value Analysis recommendations. If Council elects to proceed with the Value Analysis option identified in Table 1 as “PA VA + Lane Reduction,” (which is staff’s recommendation) the total project cost would be reduced to approximately $127,545,780. Table 6 below presents a potential funding plan to meet this revised funding need. Page 220 of 349 Item 6b Table 6 –Interchange Project’s Funding Plan for the PA VA + Lane Reduction Funding Source Current 2027-28 2028-29 2029-30 Local Funds: $15,261 $65,612,196 Capital Outlay (LRM) $15,261 Debt Finance $65,612,196 Regional Funds: $1,435,260 Regional Grant (County) $1,435,260 Developer Funds: $10,483,063 $2,000,000 $2,000,000 $11,000,000 Capital Outlay (SLR) $9,967,681 $2,000,000 $2,000,000 $11,000,000 Airport Area Impact Fee $79,205 Transportation Impact Fee $436,177 Grants: $35,000,000 Grant (SLOCOG) $10,000,000 Grant (Future) $25,000,000 Total $11,933,584 $2,000,000 $2,000,000 $111,612,196 Grand Total $127,545,780 Bridge Project Table 7 – Bridge Project’s Anticipated Costs Phase Current 2026-27 2027-28 Design $250,000 Right of Way $1,000,000 Utilities Relocation $1,750,000 Construction Admin $400,000 Construction Management $4,500,000 Construction $33,100,000 Construction Contingency $4,500,000 Total $1,250,000 $44,250,000 Grand Total $45,500,000 Table 8 – Bridge Project’s Funding Plan Funding Source Current 2026-27 2027-28 Local Funds: $7,636,760 $3,500,000 $15,358,406 Capital Outlay (IIF) $ 4,749,972 $3,500,000 $11,158,406 Capital Outlay (LRM) $ 2,277,019 $ 3,000,000 Capital Outlay $ 609,768 Developer Funds: $2,224,173 $0.00 $0.00 Airport Area Impact Fee $ 135,490 Transportation Impact Fee $ 2,088,683 Grant Funds: $2,065,000 $0.00 $15,915,661 Earmark $ 2,065,000 $58,676.00 Highway Bridge Program $15,856,9853 Total $11,925,933 $3,500,000 $30,074,067 Grand Total $45,500,000 3 Pending Highway Bridge Program programming request to address cost escalation and reimbursable portions of project. Current funding amount is $13,861,673. Page 221 of 349 Item 6b The Highway Bridge Program (HBP) is a federally funded safety program administered by Caltrans and financed through the Federal Highway Administration (FHWA). The program provides financial assistance to local agencies for the replacement or rehabilitation of publicly owned highway bridges that are structurally deficient or functionally obsolete. Caltrans evaluates bridge conditions and determines eligibility based on structural inspections and sufficiency ratings. Once a bridge is accepted into the HBP inventory, federal funds may be used to cover eligible bridge-related construction costs such as deck replacement, widening to meet standards, or seismic retrofits. Federal participation typically covers up to 88% of eligible costs, with the remaining 12% funded by the local agency. The City is requesting an increase in HBP funding to address both construction cost escalation and expansion of the participating bridge width to support multimodal improvements. This request is consistent with the City’s Active Transportation Plan (ATP), which provides strong justification for these added facilities. It should be noted that HBP funding levels fluctuate based on the eligible scope—if project elements are reduced or deemed ineligible, the corresponding federal participation amount will also decrease. ALTERNATIVES 1. Implement Value Analysis Recommendations (Estimated $8M Savings). Council could direct staff to proceed with the Interchange Project’s Preferred Alternative incorporating the Value Analysis recommendations, including use of cast-in-drilled- hole columns, long-span precast girders, a reduced bridge design speed, and increased use of recycled materials. This option would reduce the project’s estimated construction cost by approximately $8 million while maintaining all planned transportation, flood protection, and multimodal infrastructure benefits of the Preferred Alternative. No changes to the Bridge Project would be evalua ted under this option. 2. Implement Value Analysis plus Lane Reduction Modifications (Estimated $20M Savings). Council could direct staff to proceed with the Interchange Project’s Preferred Alternative incorporating all Value Analysis recommendations as well as additional modifications to reduce travel lane widths and the number of lanes on the Prado Road overpass. This option would reduce the project’s estimated construction cost by approximately $20 million (which incorporates the $8 million savings identif ied in the above alternative). This represents staff’s recommended alternative for the Prado Interchange Project. This alternative would also provide Council with the choice of whether to extend the shared-use path on the southerly side of Prado Road to Higuera Street or to terminate it at the Elks / Prado intersection. 3. Conduct a Value Analysis for the Bridge Project. Council could direct staff to complete a value analysis for the Bridge Project to identify potential opportunities for cost reduction. Staff anticipate this effort could be completed relatively quickly but may cost up to $100,000. If Council chooses to proceed, it may also wish to delegate authority to the City Manager to execute the necessary contract amendments and budget adjustments to complete the work. Page 222 of 349 Item 6b 4. Council could provide alternate direction to staff. This could the alternative recommended by the ATC at their October 25, 2025 ATC meeting. This alternative would provide more pedestrian and bicycle facilities, at a cost of at least $4 million more than the alternative recommended by staff (plus additional unknown right of way purchase costs). Staff will provide more information on this alternative at the November 4, 2025 Council meeting. ATTACHMENTS A - Preferred Alternative B - Proposed VA Refined Design C - Traffic Analysis Page 223 of 349 Page 224 of 349 Page 225 of 349 Page 226 of 349 Page 227 of 349 SECTION A-APage 228 of 349 SECTION B-BPage 229 of 349 Page 230 of 349 SENSITIVITY ANALYSIS DATE: October 23, 2025 TO: Dace Morgan | Consor FROM: Jim Damkowitch | DKS Joel Rabinovitz, PE | DKS SUBJECT: US 101 and Prado Road Interchange Project #24989-000 INTRODUCTION The following traffic analysis was completed to support the US 101 Prado Road Interchange Project. The relative performance of various design elements of the proposed project were analyzed under AM/PM peak hour 2050 future year conditions and compared across the following four performance metrics: Vehicular Level of Service (based on Highway Capacity Manual 7th Edition – HCM 7 grades using static and simulation delay results) Vehicular Delay (using both static and simulation modeling) Vehicular 95th Percentile Queue (based on simulation modeling) Carbon Footprint (based on simulation results and composite EMFAC emission rates) The peak hour volume sets used for these operational determinations were based on the most recent travel demand modeling developed by the City of San Luis Obispo. All demand profiles reflect future mode shifts to transit. Pursuant to NCHRP Report 765 Analytical Travel Forecasting Approaches for Project-Level Planning and Design, 2014, travel demand model outputs were post-processed using traffic counts collected in May 2025. The traffic counts include pedestrians and bicyclists. For the future year (2050) build condition these ped/bike counts were manually adjusted to reflect the anticipated increase in pedestrian/bicycle activity to result from the project (i.e., overcrossing connectivity and planned bicycle and pedestrian facilities in the proposed project). STUDY AREA The focus of the analysis is on Prado Road at the following two intersections: 1. Prado Road / US 101 NB Ramps 2. Prado Road / Elks Lane Page 231 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 2 Currently Elks Lane and the US 101 NB ramps intersect at an all-way-stop. With the extension of Prado Road to Froom Ranch Way (Figure 1), Elks Lane would be realigned with the City's new Water Resource Recovery Facility (WRRF) and Corporation Yard entrance. FIGURE 1: STUDY AREA PROJECT ALTERNATIVES NO BUILD The No Build alternative assumes the current all-way stop-controlled intersection at the US 101 NB off-/on-ramp / Prado Road / Elks Lane intersection, with no realignment of Elks Lane, and no overcrossing of US 101. BUILD A total of five alternatives were included in the Build analysis: two alternatives assuming a 4-lane bridge over US 101 and three alternatives with a 2-lane bridge. The Four-Lane Alternative assumed signals at the two study intersections (Figure 2), while the Two-Lane Alternative assumed either signals (Figure 3) or roundabouts (Figure 4) at the two study intersections. For each overcrossing alternative, several geometric alternatives were analyzed, as described below: Prado Road Extension Elks Lane Realignment 1 2 Page 232 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 3 FOUR-LANE OVERCROSSING Both alternatives assume a 4-lane overcrossing, with the four lanes extending from Froom Ranch Way to Higuera Street, signals at the US 101 NB ramps and Elks Lane intersections, and bike lanes and sidewalks on both sides of Prado Road. The lane configuration at both intersections is identical between alternatives, with the only difference being the treatment of the westbound right-turn at the US 101 NB ramps intersection, as described below. Alternative 1a: The westbound right-turn lane at the US 101 NB ramps would be a 200-foot storage lane, controlled at the intersection, with an approximate 100-foot long crosswalk across the east leg (Figure 2). Alternative 1b: The westbound right-turn lane would be channelized at the US 101 NB ramps (similar to Alternative 3 shown in Figure 4), have 200 feet of storage, be signalized (only for the pedestrian crossing), and include a lane add for that movement and a merge with the eastbound left and northbound thru movements (similar to Alternative 3). The crosswalk length across the east leg would be approximately 75 feet. TWO-LANE OVERCROSSING All alternatives assume a 2-lane overcrossing, with four lanes extending from east of the US 101 NB ramps to Higuera Street, bike lanes and sidewalks on both sides of Prado Road, and a two-way mixed-use path on the south side. It should be noted that options for reducing traffic lanes east of the US 101 NB ramps was initially considered, but due to the significant congestion and delays that would cause was not included in the two-lane overcrossing alternatives. Alternative 2 includes signals at the US 101 NB ramps and Elks Lane intersections, with identical lane configuration at both intersections, with the only difference being the treatment of the westbound right-turn at the US 101 NB ramps intersection, as described below. Alternative 3 would be roundabouts at Elks Lane and the US 101 NB ramps. Alternative 2a: The westbound right-turn lane at the US 101 NB ramps would be a drop lane (i.e., the rightmost lane drops to the on-ramp rather than continue through the intersection), controlled at the intersection (Figure 3). Alternative 2b: The westbound right-turn lane would be channelized at the US 101 NB ramps (similar to Alternative 3 shown in Figure 4), be signalized (only for the pedestrian crossing), and include a lane add for that movement and a merge with the eastbound left and northbound thru movements (similar to Alternative 3). Alternative 3: Alternative 3 would include a 2-lane roundabout at Elks Lane with single-lane approaches on the side street and a single-lane roundabout at the US 101 NB ramps (teardrop configuration) with a northbound right-turn lane for the off-ramp as shown in Figure 4. The westbound right at the US 101 NB ramps would be channelized, free, and include a lane add for that movement and a merge with the eastbound left and northbound thru movements. Page 233 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 4 FIGURE 2: ALTERNATIVE 1A FIGURE 3: ALTERNATIVE 2A FIGURE 4: ALTERNATIVE 3 ANALYSIS METHODOLOGY The methodologies used for the purpose of analyzing the various design elements of the proposed project alternatives are described below. Two forms of analysis were applied: static and stochastic. The static analysis is primarily based on methods described in the Highway Capacity Manual (HCM). Static analysis uses a fixed data input set along with a set of equations to develop a deterministic result versus stochastic analysis which uses a set of inputs with multi-run variance to derive a set of measured rather than calculated results (i.e., microsimulation). The SYNCHRO and SIDRA modeling software were applied for static analyses while the VISSIM modeling software was applied for stochastic operational determinations. Page 234 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 5 HIGHWAY CAPACITY MANUAL ANALYSIS The operation or performance of roadway facilities is commonly described in terms of Level of Service (LOS). LOS is a qualitative measure of effectiveness describing traffic operations based on such factors as speed, travel time, delay, and freedom to change lanes for all vehicles. Six levels are defined from LOS A, as the best-operating conditions, to LOS F, or the worst operating conditions. LOS E represents “at-capacity” operations. Study intersections were analyzed to determine their LOS based on the definitions and formulas presented in the Highway Capacity Manual 7th Edition (HCM 7) as implemented by the SYNCHRO (v12) and SIDRA (v10) analysis software. Table 1 presents the LOS criteria for intersections in accordance with the HCM 7 methodology. TABLE 1: INTERSECTION LEVEL OF SERVICE CRITERIA Notes: A. HCM 7, Chapter 19 (Signalized Intersections) B. Chapter 22 (Roundabouts) MICROSIMULATION ANALYSIS Microsimulation analysis was conducted using the VISSIM modeling software to better reflect the effects of the close intersection spacing as well as lane utilization that the HCM methodologies do not specifically address. The models were developed, and analysis was conducted in accordance with the FHWA guidelines for microsimulation analysis1. It should be noted that the VISSIM models used for this analysis were not calibrated to existing conditions. However, the VISSIM models can still be used to compare alternative results to help inform decisions for a preferred alternative. Additionally, the Existing configuration (no overcrossing, all-way stop) and future configuration (with overcrossing, signal or roundabout) are different enough that much of the calibration for the Existing condition (e.g., how drivers yield at the stop sign) would not be useful for the Future Build conditions (signal or roundabout). The driver behavior and other 1 Traffic Analysis Toolbox Volume III: Guidelines for Applying Traffic Microsimulation Modeling Software. Federal Highway Administration (FHWA). August 2003. LEVEL OF SERVICE (LOS) TOTAL DELAY PER VEHICLE (SECONDS) SIGNALIZED A UNSIGNALIZED B A < 10 < 10 B > 10 and < 20 > 10 and < 15 C > 20 and < 35 > 15 and < 25 D > 35 and < 55 > 25 and < 35 E > 55 and < 80 > 35 and < 50 F > 80 > 50 Page 235 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 6 model parameters were based on previous models developed by DKS for similar facilities. Delay results from the microsimulation analysis are compared to HCM LOS criteria for intersections for the purpose of consistency with other analysis in this report. QUEUING 95th percentile queue results are defined as the length of the queue which is exceeded five percent of the time during the analysis time period. The 95th percentile queue is useful in determining the appropriate storage requirements such as length of turn pockets but is not representative of what an average driver would experience during their commute. SYNCHRO was used to identify the average and 95th percentile vehicle queues for approaching traffic for the future peak volumes. The 95th percentile queue in SYNCHRO is a calculation of the maximum back of queue with 95th percentile traffic volume, and not an actual observed queue. VISSIM was also used to estimate the average and 95th percentile vehicle queues for approaching traffic for each study intersection for the one-hour system peak hour. To calculate 95th percentile queues, queue length data was collected from VISSIM using queue counters on critical approaches with a 120-second interval to reflect queues that form while traffic flow is impeded. The average and 95th percentile queue was then calculated using a percentile function in Excel. DKS considers micro-simulation as a superior approach for queuing analysis given its ability to more accurately reflect the operational interaction of adjacent intersections and in particular, closely spaced intersections. It is also better at reflecting the interactions of pedestrians and bicyclists at intersections of all control types and in particular those with roundabout control. FUTURE FORECASTS The peak hour volume sets used for these operational determinations were based on the most recent travel demand modeling developed by the City of San Luis Obispo. All demand profiles reflect future mode shifts to transit. Pursuant to NCHRP Report 765, travel demand model outputs were post- processed using traffic counts collected in May 2025. The traffic counts include pedestrians and bicyclists. For the future year build condition these ped/bike counts were manually adjusted to reflect the anticipated increase in pedestrian/bicycle activity to result from the project (i.e., overcrossing connectivity and planned bicycle and pedestrian facilities in the proposed project). Additionally, future forecasts included the completion of the Prado Creek Bridge project and related Higuera Street / Prado Road intersection improvements, as well as the planned extension of Prado Road east to Broad Street. Future (Year 2050) forecasts for the AM and PM peak hours for the 4-lane and 2-lane overcrossing, as shown in Figure 5 and Figure 6, respectively. Page 236 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 7 FIGURE 5: FUTURE (YEAR 2050) INTERSECTION VOLUMES – 4-LANE OVERCROSSING FIGURE 6: FUTURE (YEAR 2050) INTERSECTION VOLUMES – 2-LANE OVERCROSSING Page 237 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 8 OPERATIONAL ANALYSIS RESULTS The following section describes the intersection operations for Future Year (2050). The delay, LOS and queue results for SYNCHRO and VISSIM can be found in the Appendix. LEVEL OF SERVICE (LOS) The analysis results for the intersection performance for the Future Year (2050) AM and PM peak hours are provided in Table 2. As shown, under No Build conditions, the Prado Road / US 101 NB / Elks Lane intersection is projected to operate at LOS F during the PM peak hour with significant delay (> 2 minutes). Under Build conditions, all intersections under all scenarios and time periods would operate at LOS D or better. The 4-lane alternatives generally operate better than the 2-lane alternatives (although only by a few seconds overall), with Alternative 1B operating better of the 4- lane alternatives and Alternative 3 generally operating better of the 2-lane Alternatives. When comparing results from SYNCHRO and SIDRA (deterministic) and VISSIM (microsimulation), they are generally similar between time periods and scenarios, showing that even though the VISSIM models were not calibrated to existing conditions, the assumptions made for driver behavior are consistent with the output from SYNCHRO and SIDRA. The only exception is the NB Ramps intersection in the AM peak under Alternative 3, where the VISSIM model shows more average delay (27 seconds) for the off-ramp than SIDRA (10 seconds). This is due to a much higher delay modeled for the off-ramp in VISSIM than SIDRA. It should be noted that the circulating flow and approach flow are approximately 1,600 vph, which is the threshold at which not only dual approach lanes are necessary, but dual circulating lanes should also be considered. Page 238 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 9 TABLE 2: FUTURE YEAR (2050) INTERSECTION PERFORMANCE – DELAY AND LOS Note: A. Average delay in seconds per vehicle. Bold indicates the LOS exceeds the City’s mobility standard. B. SYNCHRO is a deterministic model and VISSIM a microsimulation model. While the results may be similar, SYNCHRO does not consider downstream queue spillback, while VISSIM does. C. The Prado Rd / Elks Ln intersection does not exist in the No Build. Elks Ln intersects Prado Rd D. Roundabout results from SIDRA. LOS based on unsignalized criteria. QUEING ANALYSIS The Future (2050) average and 95th percentile queue lengths for each intersection for the AM and PM peak hours are presented in Table 3 through Table 6. Also shown are queue lengths from SYNCHRO/SIDRA and VISSIM, with VISSIM queues generally longer than queues from SYNCHRO/SIDRA. It should be noted (and described above), the SYNCHRO/SIDRA queue lengths are calculated using equations while VISSIM queue lengths are calculated from observed queue lengths. However, the results between SYNCHRO and VISSIM are consistent in identifying movements that could experience queues in the future. INTERSECTION SOFTWARE B DELAY A (LOS) NO OC 4-LANE OC 2-LANE OC NO BUILD C ALT 1A ALT 1B ALT 2A ALT 2B ALT 3 D AM PEAK PRADO RD / US 101 NB RAMPS SYNCHRO 23 (C) 13 (B) 13 (B) 17 (B) 17 (B) 10 (A/B) VISSIM 19 (C) 13 (B) 12 (B) 20 (B/C) 18 (B) 26 (D) PRADO RD / ELKS LN SYNCHRO - 17 (B) 17 (B) 16 (B) 16 (B) 7 (A) VISSIM - 15 (B) 15 (B) 14 (B) 14 (B) 5 (A) PM PEAK PRADO RD / US 101 NB RAMPS SYNCHRO 130 (F) 16 (B) 16 (B) 19 (B) 19 (B) 13 (B) VISSIM 202 (F) 19 (B) 11 (B) 19 (B) 13 (B) 8 (A) PRADO RD / ELKS LN SYNCHRO - 26 (C) 19 (B) 21 (C) 21 (C) 10 (A/B) VISSIM - 31 (C) 27 (C) 26 (C) 24 (C) 6 (A) Page 239 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 10 AVERAGE QUEUE LENGTH As shown in the tables, average queue lengths (i.e., the queue experienced on average by a driver) are expected to be contained within the available storage and do not extend back to upstream intersections, except for the following: No Build Westbound at Prado Road / US 101 NB Ramps (PM peak) While the No Build westbound average queue does not extend to Higuera Street during the PM peak, it is within 100 feet of the intersection, meaning that at any given time during the PM peak queues are expected to extend from the US 101 NB ramps back to nearly Higuera Street. This is consistent with the high delay for this movement shown in Table 2. Alternative 1A Westbound right-turn at Prado Road / US 101 NB Ramps (PM peak) The westbound right average queue under Alternative 1A at the Prado Road / US 101 NB Ramps intersection exceeds the storage during the PM peak hour. The main reason this queue exceeds available storage is that the movement is signalized, meaning that during the eastbound left and northbound phases the movement would be red. The westbound right could therefore experience a red phase nearly 50% of the cycle (assumed 105 second cycle). While the westbound green time could be increased, it would result in longer queues for the eastbound left and northbound off-ramp. 95TH PERCENTILE QUEUE LENGTH As shown in the tables, several 95th percentile queue lengths are expected to exceed available storage or extend back to upstream intersections during both the AM and PM peak hours, as described below: No Build Westbound at Prado Road / US 101 NB Ramps (PM peak) During the PM peak, under No Build conditions, westbound queues are projected to extend back to Higuera Street. Alternative 1A Westbound right at Prado Road / US 101 NB Ramps (PM peak) Westbound through at Prado Road / US 101 NB Ramps (PM peak) Westbound through at Prado Road / Elks Lane (PM peak) The heavy westbound demand (1,800 to 1,900) during the PM peak hour results in westbound queues extending back from the US 101 NB Ramps (both in the right and through lanes) intersection to the Elks Lane intersection, and then back to the Higuera Street intersection. Alternative 1B Westbound right at Prado Road / US 101 NB Ramps (PM peak) Westbound through at Prado Road / Elks Lane (PM peak) Page 240 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 11 Similar to Alternative 1A, the westbound right-turn exceeds available storage. However, since the westbound right-turn is only stopped when there is a pedestrian, the westbound queues don’t extend all the way to the Elks Lane intersection. The heavy demand at Prado Road / Elks Lane still results in the queue extending to the Higuera Street intersection. Alternative 2A Eastbound at Prado Road / US 101 NB Ramps (AM peak) Northbound right at Prado Road / US 101 NB Ramps (AM peak) Westbound right at Prado Road / US 101 NB Ramps (PM peak) Westbound through at Prado Road / US 101 NB Ramps (PM peak) Westbound through at Prado Road / Elks Lane (PM peak) During the AM peak hour under Alternative 2A, eastbound 95th percentile queues at the Prado Road / US 101 NB Ramps would extend back toward Froom Ranch Way (2/3 of the way there in SYNCHRO and exceeding it in VISSIM). Additionally, the northbound right-turn queue (in VISSIM) would exceed available storage (200 feet) but does not result in queues back onto the US 101 NB mainline. The heavy westbound demand (1,600 to 1,700) during the PM peak hour results in westbound queues extending back from the US 101 NB Ramps (both in the right and through lanes) intersection to the Elks Lane intersection, and then back to the Higuera Street intersection. Alternative 2B Eastbound at Prado Road / US 101 NB Ramps (AM peak) Northbound right at Prado Road / US 101 NB Ramps (AM peak) Similar to Alternative 2A, during the AM peak hour the eastbound 95th percentile queue at the Prado Road / US 101 NB Ramps would extend back toward Froom Ranch Way, and the northbound right- turn queue (in VISSIM) would exceed available storage but not back onto the US 101 NB mainline. Similar to Alternative 2A, during the PM peak hour westbound queues extend back from the US 101 NB Ramps (both in the right and through lanes) intersection to the Elks Lane intersection, and then back to the Higuera Street intersection. Alternative 3 Northbound at Prado Road / US 101 NB Ramps (AM peak) The VISSIM results show northbound approach queues to the roundabout could extend back to the US 101 mainline during the AM peak hour. The reason for the queuing is that the eastbound through movement is not impeded by any other movement, and at 1,050 vehicles (100 left and 950 through) results in insufficient gaps (1 vehicle every 3-4 seconds) for northbound vehicles. Similar to Alternative 2, during the PM peak hour westbound queues extend back from the US 101 NB Ramps (both in the right and through lanes) intersection to the Elks Lane intersection. However, unlike Alternative 2, queues do not extend back to the Higuera Street intersection. Page 241 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 12 TABLE 3: FUTURE (2050) AM PEAK HOUR QUEUE LENGTHS – AVERAGE ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R PRADO RD / US 101 NB RAMPS NO BUILD (NO OC) SYNCHRO B - - - - - VISSIM - - 225 40 20 ALT 1A (4-LANE OC) SYNCHRO 30 115 - - 90 0 70 50 - - - VISSIM 60 140 - - 115 85 130 85 - - - ALT 1B (4-LANE OC) SYNCHRO 30 115 - - 90 0 70 50 - - - VISSIM 55 135 - - 115 30 120 85 - - - ALT 2A (2-LANE OC) SYNCHRO 40 275 - - 130 0 90 45 - - - VISSIM 75 410 - - 160 105 135 140 - - - ALT 2B (2-LANE OC) SYNCHRO 40 275 - - 130 0 90 45 - - - VISSIM 70 395 - - 155 20 130 135 - - - ALT 3 (2-LANE OC) SIDRA 0 - - 25 0 25 40 - - - VISSIM 0 - - 55 0 235 555 - - - PRADO RD / ELKS LN NO BUILD (NO OC) SYNCHRO - - - - VISSIM - - - - ALT 1A (4-LANE OC) SYNCHRO 10 95 5 110 5 5 10 5 VISSIM 30 265 15 185 10 5 30 25 ALT 1B (4-LANE OC) SYNCHRO 10 95 5 110 5 5 10 5 VISSIM 30 255 20 180 10 5 30 25 Page 242 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 13 Note: All queues are rounded to nearest 5’. A. L = Left. T = Thru. R = Right. B. SYNCHRO does not calculate the average queue for all-way stop intersections. ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R ALT 2A (2-LANE OC) SYNCHRO 10 75 5 40 5 5 10 5 VISSIM 30 235 20 150 10 5 30 25 ALT 2B (2-LANE OC) SYNCHRO 10 75 5 40 5 5 10 5 VISSIM 30 235 20 150 10 5 30 25 ALT 3 (2-LANE OC) SIDRA 35 15 5 5 VISSIM 70 35 15 25 Page 243 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 14 TABLE 4: FUTURE (2050) AM PEAK HOUR QUEUE LENGTHS – 95TH PERCENTILE ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R PRADO RD / US 101 NB RAMPS NO BUILD (NO OC) SYNCHRO - 235 70 10 VISSIM - 475 120 60 ALT 1A (4-LANE OC) SYNCHRO 85 200 - - 160 50 165 155 - - - VISSIM 130 235 - - 240 245 235 185 - - - ALT 1B (4-LANE OC) SYNCHRO 85 200 - - 160 50 165 155 - - - VISSIM 135 260 - - 260 145 240 190 - - - ALT 2A (2-LANE OC) SYNCHRO 90 525 - - 250 50 185 135 - - - VISSIM 140 865 - - 360 295 255 330 - - - ALT 2B (2-LANE OC) SYNCHRO 90 525 - - 250 50 185 135 - - - VISSIM 140 865 - - 350 105 250 330 - - - ALT 3 (2-LANE OC) SIDRA 0 - - 55 0 65 95 - - - VISSIM 0 - - 175 0 910 1365 - - - PRADO RD / ELKS LN NO BUILD (NO OC) SYNCHRO - - - - VISSIM - - - - ALT 1A (4-LANE OC) SYNCHRO 60 430 35 250 25 20 60 50 VISSIM 80 470 45 355 35 20 80 65 ALT 1B (4-LANE OC) SYNCHRO 60 430 35 250 25 20 60 50 VISSIM 85 515 60 355 40 25 85 75 SYNCHRO 55 345 35 190 20 20 55 45 Page 244 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 15 Note: All queues are rounded to nearest 5’. BOLD indicates the queue exceeds the storage length or extends back to the next upstream intersection. A. L = Left. T = Thru. R = Right. ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R ALT 2A (2-LANE OC) VISSIM 80 585 50 315 45 25 90 70 ALT 2B (2-LANE OC) SYNCHRO 55 345 35 190 20 20 55 45 VISSIM 80 585 20 150 45 25 90 70 ALT 3 (2-LANE OC) SIDRA 85 40 5 10 VISSIM 130 115 50 90 Page 245 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 16 TABLE 5: FUTURE (2050) PM PEAK HOUR QUEUE LENGTHS – AVERAGE ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R PRADO RD / US 101 NB RAMPS NO BUILD (NO OC) SYNCHRO B - - - - VISSIM - 1545 10 20 ALT 1A (4-LANE OC) SYNCHRO 50 50 - - 205 45 90 0 - - - VISSIM 65 60 - - 310 430 110 35 - - - ALT 1B (4-LANE OC) SYNCHRO 50 50 - - 205 45 90 0 - - - VISSIM 60 60 - - 220 115 95 40 - - - ALT 2A (2-LANE OC) SYNCHRO 55 115 - - 430 45 95 0 - - - VISSIM 60 130 - - 435 460 105 40 - - - ALT 2B (2-LANE OC) SYNCHRO 55 115 - - 430 45 95 0 - - - VISSIM 60 130 - - 390 120 105 40 - - - ALT 3 (2-LANE OC) SIDRA 0 - - 275 0 10 10 - - - VISSIM 0 - - 295 10 45 45 - - - PRADO RD / ELKS LN NO BUILD (NO OC) SYNCHRO - - - - VISSIM - - - - ALT 1A (4-LANE OC) SYNCHRO 30 80 5 530 20 15 30 5 VISSIM 45 105 10 665 25 20 40 35 ALT 1B (4-LANE OC) SYNCHRO 30 80 5 530 20 15 30 5 VISSIM 40 105 10 610 25 20 40 35 SYNCHRO 30 75 5 420 20 15 30 5 Page 246 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 17 Note: All queues are rounded to nearest 5’. BOLD indicates the queue exceeds the storage length or extends back to the next upstream intersection. A. L = Left. T = Thru. R = Right. B. SYNCHRO does not calculate the average queue for all-way stop intersections. ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R ALT 2A (2-LANE OC) VISSIM 45 100 10 550 25 20 45 35 ALT 2B (2-LANE OC) SYNCHRO 30 75 5 420 20 15 30 5 VISSIM 40 100 10 525 25 20 45 30 ALT 3 (2-LANE OC) SIDRA 15 60 5 15 VISSIM 50 160 20 50 Page 247 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 18 TABLE 6: FUTURE (2050) PM PEAK HOUR QUEUE LENGTHS – 95TH PERCENTILE ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R PRADO RD / US 101 NB RAMPS NO BUILD (NO OC) SYNCHRO - 950 20 10 VISSIM - 1690 60 60 ALT 1A (4-LANE OC) SYNCHRO 110 85 - - 335 235 175 50 - - - VISSIM 135 115 - - 715 725 210 85 - - - ALT 1B (4-LANE OC) SYNCHRO 110 85 - - 335 220 175 50 - - - VISSIM 135 130 - - 545 495 205 95 - - - ALT 2A (2-LANE OC) SYNCHRO 110 215 - - #845 B 230 175 50 - - - VISSIM 135 300 - - 740 740 205 105 - - - ALT 2B (2-LANE OC) SYNCHRO 110 215 - - #845 B 215 175 50 - - - VISSIM 135 325 - - 720 645 200 105 - - - ALT 3 (2-LANE OC) SIDRA 0 - - 675 0 25 20 - - - VISSIM 0 - - 740 80 125 120 - - - PRADO RD / ELKS LN NO BUILD (NO OC) SYNCHRO - - - - VISSIM - - - - ALT 1A (4-LANE OC) SYNCHRO 75 175 25 #820 B 50 50 75 50 VISSIM 105 240 45 950 65 70 95 90 ALT 1B (4-LANE OC) SYNCHRO 75 175 25 #815 B 50 50 75 50 VISSIM 105 210 45 945 70 70 90 90 SYNCHRO 75 170 25 605 50 50 75 50 Page 248 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 19 Note: All queues are rounded to nearest 5’. BOLD indicates the queue exceeds the storage length or extends back to the next upstream intersection. A. L = Left. T = Thru. R = Right. B. # = 95th percentile volume exceeds capacity, queue may be longer. ALTERNATIVE SOFTWARE QUEUE LENGTH (FT) A EASTBOUND WESTBOUND NORTHBOUND SOUTHBOUND L T R L T R L T R L T R ALT 2A (2-LANE OC) VISSIM 105 220 45 945 65 65 90 95 ALT 2B (2-LANE OC) SYNCHRO 75 170 25 605 50 50 75 50 VISSIM 105 200 45 940 65 70 100 85 ALT 3 (2-LANE OC) SIDRA 40 155 10 35 VISSIM 105 550 75 135 Page 249 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 20 GREEN HOUSE GAS (GHG) EMISSIONS ANALYSIS Reducing the effects of climate change and specifically reducing on-road mobile source emissions of greenhouse gases is a key policy initiative of both Caltrans and the City of San Luis Obispo. As such, a generalized “carbon footprint” assessment was performed for each design alternative. This analysis entailed generating composite emission rates specific to San Luis Obispo’s motor vehicle fleet demographic, fuel type (i.e., gas, diesel, electric, etc.) and technology group distributions. Given that the latest Emission Factors (EMFAC) model from the California Air Resources Board (EMFAC25) reflects currently rescinded or pending regulations affecting EV adoption rates, a 2025 analysis year was preferred over an outyear forecast. Hence, 2025 composite emission rates were applied to 2050 forecasts of vehicle activity. As shown in Table 7, the 2050 VISSIM microsimulation vehicle activity output for both AM and PM peak hours was allocated to the appropriate speed bin. This activity is multiplied by the EMFAC25 composite emission rate associated with each speed bin to generate total CO2 missions2. The final results are tallied at the bottom of the table and expressed in tons (AM and PM Peak Hour combined). The results indicate that Alternative 2B generates the least amount of peak hour CO2 (smallest carbon footprint). The No Build condition is not reported as it is not comparable within Vissim to the other alternatives given there is no overcrossing. An emissions comparison would require a much larger area to capture the changes in travel patterns with the overcrossing, which is beyond the scope of this analysis. 2 Of the three GHG components (Carbon dioxide (CO2), Methane (CH4), and Nitrous oxide (N2O)) only CO2 was modeled. Page 250 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 21 TABLE 7: 2050 EMISSIONS COMPARISON SPEED BIN PEAK HOUR 2025 COMPOSITE EMMISION CO2 RATE (G/MI) A 2050 VMT 4-LANE OC 2-LANE OC ALT 1A ALT 1B ALT 2A ALT 2B ALT 3 0-5 MPH AM 864.88 95 96 96 96 328 PM 122 96 95 95 24 6-15 MPH AM 628.23 2820 2162 2953 2271 1760 PM 6277 2125 4923 1924 1280 16-35 MPH AM 409.48 14895 15537 14234 14931 14871 PM 14850 19044 16330 19353 18596 35+ MPH AM 299.89 1207 1210 1409 1410 3777 PM 3066 3071 2523 2524 3876 Total Emissions (tons) - 21.3 20.2 20.7 19.9 20.1 Note: A. Composite of LDA, LDT1 and LDT2, LHD1 and LHD1 Other, MCY, MDV vehicle population mix SUMMARY The operational results presented above show that the Build Alternatives generally operate better than the No Build. Table 8 provides a performance summary of all Alternatives for delay, average and 95th percentile queue, and GHG Emissions. The following is a summary of how the performance measures were quantified: LOS Excellent Performance is if the intersection operates at LOS D or better and all movements are better than LOS F Acceptable Performance is if there are any LOS F movements, but the intersection still operates better than LOS D Moderate Performance is if the intersection operates worse than LOS D but not at LOS F Poor Performance is if the intersection operates at LOS F Average / 95th Percentile Queue Excellent Performance if queues are contained within storage and no queues extend to an upstream intersection Acceptable Performance if a storage lane is exceeded or queues back to upstream intersection, but not to Higuera Street Moderate Performance if a queue extends back to Higuera Street Poor Performance if a queue backs onto US 101 Page 251 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 22 Emissions Excellent Performance if less than 20 tons of emissions Acceptable Performance if between 20 and 21 tons of emissions Moderate Performance if between 21 and 22 tons of emissions Poor Performance if greater than 22 tons of emissions The results show that Alternative 2B (2-lane overcrossing with westbound right at the US 101 NB ramps channelized) generally performs better than the other Alternatives. It should be noted that while Alternative 3 performs similarly to Alternative 2B, the 95th percentile queue on the US 101 NB off-ramp extends back onto US 101, making this a fatal flaw without additional mitigation (e.g., additional lanes or signalizing the roundabout to manage queues) to reduce the queue spillback onto US 101. This would require additional costs and no longer meet the intent of the Alternative (smaller footprint of the overcrossing). TABLE 8: PERFORMANCE SUMMARY MEASURE OF EFFECTIVENESS ALTERNATIVE A NO BUILD ALT 1A ALT 1B ALT 2A ALT 2B ALT 3 DELAY B AVG QUEUE LENGTH (SYNCHRO/SIDRA) N/A AVG QUEUE LENGTH (VISSIM) 95% QUEUE LENGTH (SYNCHRO/SIDRA) 95% QUEUE LENGTH (VISSIM) EMMISSIONS N/A C C Note: A. = Excellent Performance, = Acceptable Performance, = Moderate Performance, = Poor Performance B. Delay comes from the Synchro/Sidra software. C. These Alternatives ranked as acceptable performance based on total emissions, but was considered excellent performance as they involve less GHG generation during construction. Page 252 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 APPENDIX CONTENTS Section 1: SYNCHRO/Sidra Results Section 2: VISSIM Results Page 253 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 SECTION 1: SYNCHRO/SIDRA RESULTS Page 254 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 NO BUILD AM PEAK HOUR Page 255 of 349 HCM 7th AWSC 3: US 101 NB Off/Elks Lane & Prado Rd 0_No Build AM City of SLO - US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Intersection Intersection Delay, s/veh 22.8 Intersection LOS C Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Vol, veh/h 00005651503031055015 Future Vol, veh/h 00005651503031055015 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Heavy Vehicles, % 2224101045520420 Mvmt Flow 00005651503031055015 Number of Lanes 000010010101 Approach WB NB SB Opposing Approach SB NB Opposing Lanes 0 2 1 Conflicting Approach Left NB WB Conflicting Lanes Left 1 0 1 Conflicting Approach Right SB WB Conflicting Lanes Right 2 1 0 HCM Control Delay, s/veh 29.6 13.7 10.9 HCM LOS D B B Lane NBLn1 WBLn1 SBLn1 SBLn2 Vol Left, %0% 0% 100% 0% Vol Thru, %9% 97% 0% 0% Vol Right, %91% 3% 0% 100% Sign Control Stop Stop Stop Stop Traffic Vol by Lane 340 580 55 15 LT Vol 0 0 55 0 Through Vol 30 565 0 0 RT Vol 310 15 0 15 Lane Flow Rate 340 580 55 15 Geometry Grp 4a255 Degree of Util (X)0.503 0.841 0.115 0.026 Departure Headway (Hd)5.323 5.219 7.546 6.32 Convergence, Y/N Yes Yes Yes Yes Cap 677 696 474 565 Service Time 3.366 3.248 5.306 4.079 HCM Lane V/C Ratio 0.502 0.833 0.116 0.027 HCM Control Delay, s/veh 13.7 29.6 11.3 9.2 HCM Lane LOS B D B A HCM 95th-tile Q 2.8 9.4 0.4 0.1 Page 256 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 NO BUILD PM PEAK HOUR Page 257 of 349 HCM 7th AWSC 3: US 101 NB Off/Elks Lane & Prado Rd 0_No Build PM City of SLO - US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Intersection Intersection Delay, s/veh 130.2 Intersection LOS F Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Vol, veh/h 00009803001012545025 Future Vol, veh/h 00009803001012545025 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Heavy Vehicles, % 22245525510410 Mvmt Flow 00009803001012545025 Number of Lanes 000010010101 Approach WB NB SB Opposing Approach SB NB Opposing Lanes 0 2 1 Conflicting Approach Left NB WB Conflicting Lanes Left 1 0 1 Conflicting Approach Right SB WB Conflicting Lanes Right 2 1 0 HCM Control Delay, s/veh 154.4 10.9 11 HCM LOS F B B Lane NBLn1 WBLn1 SBLn1 SBLn2 Vol Left, %0% 0% 100% 0% Vol Thru, %7% 97% 0% 0% Vol Right, %93% 3% 0% 100% Sign Control Stop Stop Stop Stop Traffic Vol by Lane 135 1010 45 25 LT Vol 0 0 45 0 Through Vol 10 980 0 0 RT Vol 125 30 0 25 Lane Flow Rate 135 1010 45 25 Geometry Grp 4a255 Degree of Util (X)0.209 1.286 0.091 0.042 Departure Headway (Hd)6.252 4.584 8.048 6.814 Convergence, Y/N Yes Yes Yes Yes Cap 578 798 448 529 Service Time 4.252 2.603 5.748 4.514 HCM Lane V/C Ratio 0.234 1.266 0.1 0.047 HCM Control Delay, s/veh 10.9 154.4 11.6 9.8 HCM Lane LOS B F B A HCM 95th-tile Q 0.8 37.9 0.3 0.1 Page 258 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1A AM PEAK HOUR Page 259 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1A AM City of SLO - US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h) 100 1150 0 0 620 350 240 0 300 0 0 0 Future Volume (veh/h) 100 1150 0 0 620 350 240 0 300 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 0.94 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 1150 0 0 620 350 240 0 300 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, % 4 4 0 0 4 4 4 0 4 Cap, veh/h 158 1944 0 0 1279 538 429 0 381 Arrive On Green 0.09 0.56 0.00 0.00 0.37 0.37 0.24 0.00 0.24 Sat Flow, veh/h 1753 3589 0 0 3589 1472 1753 0 1560 Grp Volume(v), veh/h 100 1150 0 0 620 350 240 0 300 Grp Sat Flow(s),veh/h/ln 1753 1749 0 0 1749 1472 1753 0 1560 Q Serve(g_s), s 2.8 10.9 0.0 0.0 6.8 9.9 6.0 0.0 9.0 Cycle Q Clear(g_c), s 2.8 10.9 0.0 0.0 6.8 9.9 6.0 0.0 9.0 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 158 1944 0 0 1279 538 429 0 381 V/C Ratio(X)0.63 0.59 0.00 0.00 0.48 0.65 0.56 0.00 0.79 Avail Cap(c_a), veh/h 700 3493 0 0 3493 1470 700 0 623 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 22.0 7.4 0.0 0.0 12.2 13.2 16.6 0.0 17.7 Incr Delay (d2), s/veh 4.2 0.3 0.0 0.0 0.3 1.3 1.1 0.0 3.6 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.2 2.7 0.0 0.0 2.2 2.8 2.1 0.0 3.0 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 26.1 7.6 0.0 0.0 12.5 14.5 17.7 0.0 21.3 LnGrp LOS C A B B B C Approach Vol, veh/h 1250 970 540 Approach Delay, s/veh 9.1 13.2 19.7 Approach LOS A B B Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 32.8 9.5 23.3 17.2 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 12.9 4.8 11.9 11.0 Green Ext Time (p_c), s 10.4 0.2 6.3 1.2 Intersection Summary HCM 7th Control Delay, s/veh 12.6 HCM 7th LOS B Page 260 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd Alt 1A AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)40 1370 40 20 930 20 10 5 5 40 20 30 Future Volume (veh/h)40 1370 40 20 930 20 10 5 5 40 20 30 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.95 1.00 0.95 1.00 0.96 1.00 0.97 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 40 1370 40 20 930 20 10 5 5 40 20 30 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 79 1768 52 48 1722 37 26 129 129 79 121 182 Arrive On Green 0.04 0.51 0.51 0.03 0.49 0.49 0.02 0.16 0.16 0.04 0.19 0.19 Sat Flow, veh/h 1753 3464 101 1753 3496 75 1753 827 827 1753 651 976 Grp Volume(v), veh/h 40 691 719 20 465 485 10 0 10 40 0 50 Grp Sat Flow(s),veh/h/ln 1753 1749 1817 1753 1749 1823 1753 0 1653 1753 0 1627 Q Serve(g_s), s 1.7 24.5 24.6 0.9 14.1 14.1 0.4 0.0 0.4 1.7 0.0 2.0 Cycle Q Clear(g_c), s 1.7 24.5 24.6 0.9 14.1 14.1 0.4 0.0 0.4 1.7 0.0 2.0 Prop In Lane 1.00 0.06 1.00 0.04 1.00 0.50 1.00 0.60 Lane Grp Cap(c), veh/h 79 893 927 48 861 898 26 0 258 79 0 303 V/C Ratio(X)0.51 0.77 0.78 0.42 0.54 0.54 0.38 0.00 0.04 0.51 0.00 0.17 Avail Cap(c_a), veh/h 229 1371 1424 229 1371 1429 229 0 540 229 0 531 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 35.7 15.2 15.2 36.6 13.4 13.4 37.3 0.0 27.4 35.7 0.0 26.2 Incr Delay (d2), s/veh 5.0 1.5 1.5 5.8 0.5 0.5 8.8 0.0 0.1 5.0 0.0 0.3 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 0.8 8.7 9.1 0.4 5.0 5.2 0.2 0.0 0.2 0.8 0.0 0.8 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 40.7 16.7 16.7 42.4 13.9 13.9 46.1 0.0 27.5 40.7 0.0 26.4 LnGrp LOS D B B D B B D C D C Approach Vol, veh/h 1450 970 20 90 Approach Delay, s/veh 17.3 14.5 36.8 32.8 Approach LOS B B D C Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 7.1 44.1 6.1 19.2 8.4 42.7 8.4 17.0 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.9 26.6 2.4 4.0 3.7 16.1 3.7 2.4 Green Ext Time (p_c), s 0.0 12.5 0.0 0.2 0.0 7.2 0.0 0.0 Intersection Summary HCM 7th Control Delay, s/veh 17.0 HCM 7th LOS B Page 261 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1A AM City of SLO - US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph) 100 1150 620 350 240 300 v/c Ratio 0.35 0.59 0.49 0.47 0.55 0.63 Control Delay (s/veh) 28.7 9.5 17.2 4.5 26.3 19.5 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh) 28.7 9.5 17.2 4.5 26.3 19.5 Queue Length 50th (ft) 31 114 88 0 72 52 Queue Length 95th (ft) 86 201 162 51 167 153 Internal Link Dist (ft)786 602 Turn Bay Length (ft) 150 150 300 Base Capacity (vph) 648 3458 2976 1272 648 655 Starvation Cap Reductn 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.15 0.33 0.21 0.28 0.37 0.46 Intersection Summary Page 262 of 349 Queues 6: Elks Lane & Prado Rd Alt 1A AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)40 1410 20 950 10 10 40 50 v/c Ratio 0.17 0.54 0.09 0.39 0.05 0.04 0.17 0.20 Control Delay (s/veh)35.5 9.2 37.1 9.4 37.8 30.1 35.5 22.3 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)35.5 9.2 37.1 9.4 37.8 30.1 35.5 22.3 Queue Length 50th (ft)11 97 5 111 3 1 11 5 Queue Length 95th (ft)60 431 37 251 24 20 60 50 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)326 3024 326 3029 326 779 326 776 Starvation Cap Reductn 0 54 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.12 0.47 0.06 0.31 0.03 0.01 0.12 0.06 Intersection Summary Page 263 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1A PM PEAK HOUR Page 264 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1A PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 610 0 0 1110 780 180 0 150 0 0 0 Future Volume (veh/h)100 610 0 0 1110 780 180 0 150 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.96 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 610 0 0 1110 780 180 0 150 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 130 2566 0 0 2076 886 236 0 210 Arrive On Green 0.07 0.73 0.00 0.00 0.59 0.59 0.13 0.00 0.13 Sat Flow, veh/h 1753 3589 0 0 3589 1493 1753 0 1560 Grp Volume(v), veh/h 100 610 0 0 1110 780 180 0 150 Grp Sat Flow(s),veh/h/ln 1753 1749 0 0 1749 1493 1753 0 1560 Q Serve(g_s), s 4.3 4.3 0.0 0.0 14.4 33.8 7.5 0.0 7.0 Cycle Q Clear(g_c), s 4.3 4.3 0.0 0.0 14.4 33.8 7.5 0.0 7.0 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 130 2566 0 0 2076 886 236 0 210 V/C Ratio(X)0.77 0.24 0.00 0.00 0.53 0.88 0.76 0.00 0.71 Avail Cap(c_a), veh/h 461 2566 0 0 2301 982 461 0 410 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 34.5 3.3 0.0 0.0 9.2 13.1 31.7 0.0 31.5 Incr Delay (d2), s/veh 9.0 0.0 0.0 0.0 0.2 8.7 5.0 0.0 4.5 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 2.1 0.9 0.0 0.0 4.5 11.1 3.3 0.0 2.7 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 43.6 3.3 0.0 0.0 9.4 21.8 36.7 0.0 35.9 LnGrp LOS D A A C D D Approach Vol, veh/h 710 1890 330 Approach Delay, s/veh 9.0 14.5 36.4 Approach LOS A B D Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 60.8 10.7 50.1 15.2 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 6.3 6.3 35.8 9.5 Green Ext Time (p_c), s 4.6 0.2 9.3 0.7 Intersection Summary HCM 7th Control Delay, s/veh 15.6 HCM 7th LOS B Page 265 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd Alt 1A PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)50 700 10 10 1800 20 30 20 20 50 10 60 Future Volume (veh/h)50 700 10 10 1800 20 30 20 20 50 10 60 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.96 1.00 0.96 1.00 0.96 1.00 0.96 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 50 700 10 10 1800 20 30 20 20 50 10 60 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 79 2108 30 26 2008 22 59 118 118 79 34 203 Arrive On Green 0.05 0.60 0.60 0.01 0.57 0.57 0.03 0.14 0.14 0.05 0.15 0.15 Sat Flow, veh/h 1753 3527 50 1753 3541 39 1753 825 825 1753 220 1320 Grp Volume(v), veh/h 50 347 363 10 887 933 30 0 40 50 0 70 Grp Sat Flow(s),veh/h/ln 1753 1749 1829 1753 1749 1832 1753 0 1650 1753 0 1540 Q Serve(g_s), s 2.8 10.0 10.0 0.6 44.6 44.9 1.7 0.0 2.1 2.8 0.0 4.0 Cycle Q Clear(g_c), s 2.8 10.0 10.0 0.6 44.6 44.9 1.7 0.0 2.1 2.8 0.0 4.0 Prop In Lane 1.00 0.03 1.00 0.02 1.00 0.50 1.00 0.86 Lane Grp Cap(c), veh/h 79 1045 1093 26 992 1039 59 0 235 79 0 237 V/C Ratio(X)0.63 0.33 0.33 0.39 0.89 0.90 0.50 0.00 0.17 0.63 0.00 0.30 Avail Cap(c_a), veh/h 175 1050 1098 175 1050 1099 175 0 413 175 0 385 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 46.9 10.1 10.1 48.8 19.0 19.1 47.5 0.0 37.6 46.9 0.0 37.5 Incr Delay (d2), s/veh 8.1 0.2 0.2 9.5 9.7 9.6 6.5 0.0 0.3 8.1 0.0 0.7 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.4 3.6 3.7 0.3 18.7 19.7 0.8 0.0 0.9 1.4 0.0 1.6 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 55.0 10.3 10.3 58.3 28.7 28.7 53.9 0.0 38.0 55.0 0.0 38.2 LnGrp LOS E B B E C C D D E D Approach Vol, veh/h 760 1830 70 120 Approach Delay, s/veh 13.2 28.9 44.8 45.2 Approach LOS B C D D Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 6.5 64.7 8.4 20.4 9.5 61.7 9.5 19.3 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.6 12.0 3.7 6.0 4.8 46.9 4.8 4.1 Green Ext Time (p_c), s 0.0 4.8 0.0 0.3 0.0 9.8 0.0 0.1 Intersection Summary HCM 7th Control Delay, s/veh 25.7 HCM 7th LOS C Page 266 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1A PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 610 1110 780 180 150 v/c Ratio 0.42 0.26 0.61 0.75 0.57 0.37 Control Delay (s/veh)42.2 5.0 16.2 9.2 41.4 9.2 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)42.2 5.0 16.2 9.2 41.4 9.2 Queue Length 50th (ft)50 50 203 45 89 0 Queue Length 95th (ft)109 86 334 237 173 52 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 150 300 Base Capacity (vph)498 3077 2319 1155 498 552 Starvation Cap Reductn 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.20 0.20 0.48 0.68 0.36 0.27 Intersection Summary Page 267 of 349 Queues 6: Elks Lane & Prado Rd Alt 1A PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)50 710 10 1820 30 40 50 70 v/c Ratio 0.35 0.27 0.09 0.78 0.23 0.27 0.35 0.38 Control Delay (s/veh)52.6 6.7 49.5 20.3 50.5 33.2 52.6 21.8 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)52.6 6.7 49.5 20.3 50.5 33.2 52.6 21.8 Queue Length 50th (ft)32 79 6 530 19 13 32 6 Queue Length 95th (ft)73 174 25 #818 51 48 73 51 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)179 2617 179 2324 179 443 179 441 Starvation Cap Reductn 0 0 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.28 0.27 0.06 0.78 0.17 0.09 0.28 0.16 Intersection Summary # 95th percentile volume exceeds capacity, queue may be longer. Queue shown is maximum after two cycles. Page 268 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1B AM PEAK HOUR Page 269 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1B AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 1150 0 0 620 350 240 0 300 0 0 0 Future Volume (veh/h)100 1150 0 0 620 350 240 0 300 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.94 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 1150 0 0 620 350 240 0 300 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 158 1944 0 0 1279 538 429 0 381 Arrive On Green 0.09 0.56 0.00 0.00 0.37 0.37 0.24 0.00 0.24 Sat Flow, veh/h 1753 3589 0 0 3589 1472 1753 0 1560 Grp Volume(v), veh/h 100 1150 0 0 620 350 240 0 300 Grp Sat Flow(s),veh/h/ln 1753 1749 0 0 1749 1472 1753 0 1560 Q Serve(g_s), s 2.8 10.9 0.0 0.0 6.8 9.9 6.0 0.0 9.0 Cycle Q Clear(g_c), s 2.8 10.9 0.0 0.0 6.8 9.9 6.0 0.0 9.0 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 158 1944 0 0 1279 538 429 0 381 V/C Ratio(X)0.63 0.59 0.00 0.00 0.48 0.65 0.56 0.00 0.79 Avail Cap(c_a), veh/h 700 3493 0 0 3493 1470 700 0 623 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 22.0 7.4 0.0 0.0 12.2 13.2 16.6 0.0 17.7 Incr Delay (d2), s/veh 4.2 0.3 0.0 0.0 0.3 1.3 1.1 0.0 3.6 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.2 2.7 0.0 0.0 2.2 2.8 2.1 0.0 3.0 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 26.1 7.6 0.0 0.0 12.5 14.5 17.7 0.0 21.3 LnGrp LOS C A B B B C Approach Vol, veh/h 1250 970 540 Approach Delay, s/veh 9.1 13.2 19.7 Approach LOS A B B Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 32.8 9.5 23.3 17.2 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 12.9 4.8 11.9 11.0 Green Ext Time (p_c), s 10.4 0.2 6.3 1.2 Intersection Summary HCM 7th Control Delay, s/veh 12.6 HCM 7th LOS B Page 270 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd Alt 1B AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)40 1370 40 20 930 20 10 5 5 40 20 30 Future Volume (veh/h)40 1370 40 20 930 20 10 5 5 40 20 30 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.95 1.00 0.95 1.00 0.96 1.00 0.97 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 40 1370 40 20 930 20 10 5 5 40 20 30 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 79 1768 52 48 1722 37 26 129 129 79 121 182 Arrive On Green 0.04 0.51 0.51 0.03 0.49 0.49 0.02 0.16 0.16 0.04 0.19 0.19 Sat Flow, veh/h 1753 3464 101 1753 3496 75 1753 827 827 1753 651 976 Grp Volume(v), veh/h 40 691 719 20 465 485 10 0 10 40 0 50 Grp Sat Flow(s),veh/h/ln 1753 1749 1817 1753 1749 1823 1753 0 1653 1753 0 1627 Q Serve(g_s), s 1.7 24.5 24.6 0.9 14.1 14.1 0.4 0.0 0.4 1.7 0.0 2.0 Cycle Q Clear(g_c), s 1.7 24.5 24.6 0.9 14.1 14.1 0.4 0.0 0.4 1.7 0.0 2.0 Prop In Lane 1.00 0.06 1.00 0.04 1.00 0.50 1.00 0.60 Lane Grp Cap(c), veh/h 79 893 927 48 861 898 26 0 258 79 0 303 V/C Ratio(X)0.51 0.77 0.78 0.42 0.54 0.54 0.38 0.00 0.04 0.51 0.00 0.17 Avail Cap(c_a), veh/h 229 1371 1424 229 1371 1429 229 0 540 229 0 531 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 35.7 15.2 15.2 36.6 13.4 13.4 37.3 0.0 27.4 35.7 0.0 26.2 Incr Delay (d2), s/veh 5.0 1.5 1.5 5.8 0.5 0.5 8.8 0.0 0.1 5.0 0.0 0.3 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 0.8 8.7 9.1 0.4 5.0 5.2 0.2 0.0 0.2 0.8 0.0 0.8 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 40.7 16.7 16.7 42.4 13.9 13.9 46.1 0.0 27.5 40.7 0.0 26.4 LnGrp LOS D B B D B B D C D C Approach Vol, veh/h 1450 970 20 90 Approach Delay, s/veh 17.3 14.5 36.8 32.8 Approach LOS B B D C Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 7.1 44.1 6.1 19.2 8.4 42.7 8.4 17.0 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.9 26.6 2.4 4.0 3.7 16.1 3.7 2.4 Green Ext Time (p_c), s 0.0 12.5 0.0 0.2 0.0 7.2 0.0 0.0 Intersection Summary HCM 7th Control Delay, s/veh 17.0 HCM 7th LOS B Page 271 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1B AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 1150 620 350 240 300 v/c Ratio 0.35 0.59 0.49 0.46 0.55 0.63 Control Delay (s/veh)28.7 9.5 17.2 4.4 26.3 19.5 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)28.7 9.5 17.2 4.4 26.3 19.5 Queue Length 50th (ft)31 114 88 0 72 52 Queue Length 95th (ft)86 201 162 51 167 153 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 150 300 Base Capacity (vph)648 3458 2976 1316 648 655 Starvation Cap Reductn 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.15 0.33 0.21 0.27 0.37 0.46 Intersection Summary Page 272 of 349 Queues 6: Elks Lane & Prado Rd Alt 1B AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)40 1410 20 950 10 10 40 50 v/c Ratio 0.17 0.54 0.09 0.39 0.05 0.04 0.17 0.20 Control Delay (s/veh)35.5 9.2 37.1 9.4 37.8 30.1 35.5 22.3 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)35.5 9.2 37.1 9.4 37.8 30.1 35.5 22.3 Queue Length 50th (ft)11 97 5 111 3 1 11 5 Queue Length 95th (ft)60 431 37 251 24 20 60 50 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)326 3024 326 3029 326 779 326 776 Starvation Cap Reductn 0 54 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.12 0.47 0.06 0.31 0.03 0.01 0.12 0.06 Intersection Summary Page 273 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1B PM PEAK HOUR Page 274 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1B PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 610 0 0 1110 780 180 0 150 0 0 0 Future Volume (veh/h)100 610 0 0 1110 780 180 0 150 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.96 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 610 0 0 1110 780 180 0 150 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 130 2566 0 0 2076 886 236 0 210 Arrive On Green 0.07 0.73 0.00 0.00 0.59 0.59 0.13 0.00 0.13 Sat Flow, veh/h 1753 3589 0 0 3589 1493 1753 0 1560 Grp Volume(v), veh/h 100 610 0 0 1110 780 180 0 150 Grp Sat Flow(s),veh/h/ln 1753 1749 0 0 1749 1493 1753 0 1560 Q Serve(g_s), s 4.3 4.3 0.0 0.0 14.4 33.8 7.5 0.0 7.0 Cycle Q Clear(g_c), s 4.3 4.3 0.0 0.0 14.4 33.8 7.5 0.0 7.0 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 130 2566 0 0 2076 886 236 0 210 V/C Ratio(X)0.77 0.24 0.00 0.00 0.53 0.88 0.76 0.00 0.71 Avail Cap(c_a), veh/h 461 2566 0 0 2301 982 461 0 410 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 34.5 3.3 0.0 0.0 9.2 13.1 31.7 0.0 31.5 Incr Delay (d2), s/veh 9.0 0.0 0.0 0.0 0.2 8.7 5.0 0.0 4.5 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 2.1 0.9 0.0 0.0 4.5 11.1 3.3 0.0 2.7 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 43.6 3.3 0.0 0.0 9.4 21.8 36.7 0.0 35.9 LnGrp LOS D A A C D D Approach Vol, veh/h 710 1890 330 Approach Delay, s/veh 9.0 14.5 36.4 Approach LOS A B D Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 60.8 10.7 50.1 15.2 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 6.3 6.3 35.8 9.5 Green Ext Time (p_c), s 4.6 0.2 9.3 0.7 Intersection Summary HCM 7th Control Delay, s/veh 15.6 HCM 7th LOS B Page 275 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd Alt 1B PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)50 700 10 10 1800 20 30 20 20 50 10 60 Future Volume (veh/h)50 700 10 10 1800 20 30 20 20 50 10 60 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 50 700 10 10 1800 20 30 20 20 50 10 60 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 84 2234 32 26 2124 24 62 65 65 84 20 123 Arrive On Green 0.05 0.63 0.63 0.01 0.60 0.60 0.04 0.08 0.08 0.05 0.09 0.09 Sat Flow, veh/h 1753 3530 50 1753 3543 39 1753 844 844 1753 228 1367 Grp Volume(v), veh/h 50 347 363 10 887 933 30 0 40 50 0 70 Grp Sat Flow(s),veh/h/ln 1753 1749 1832 1753 1749 1834 1753 0 1689 1753 0 1595 Q Serve(g_s), s 2.5 8.0 8.0 0.5 36.3 36.5 1.5 0.0 2.0 2.5 0.0 3.7 Cycle Q Clear(g_c), s 2.5 8.0 8.0 0.5 36.3 36.5 1.5 0.0 2.0 2.5 0.0 3.7 Prop In Lane 1.00 0.03 1.00 0.02 1.00 0.50 1.00 0.86 Lane Grp Cap(c), veh/h 84 1106 1159 26 1048 1099 62 0 130 84 0 143 V/C Ratio(X)0.59 0.31 0.31 0.39 0.85 0.85 0.48 0.00 0.31 0.59 0.00 0.49 Avail Cap(c_a), veh/h 199 1193 1249 199 1193 1251 199 0 480 199 0 453 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 41.0 7.4 7.4 42.9 14.3 14.4 41.6 0.0 38.4 41.0 0.0 38.1 Incr Delay (d2), s/veh 6.5 0.2 0.2 9.1 5.3 5.1 5.7 0.0 1.3 6.5 0.0 2.6 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.2 2.6 2.7 0.3 13.6 14.3 0.7 0.0 0.9 1.2 0.0 1.5 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 47.5 7.6 7.6 52.1 19.6 19.5 47.3 0.0 39.7 47.5 0.0 40.7 LnGrp LOS D A A D B B D D D D Approach Vol, veh/h 760 1830 70 120 Approach Delay, s/veh 10.2 19.7 43.0 43.5 Approach LOS B B D D Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 6.3 60.7 8.1 12.9 9.2 57.7 9.2 11.8 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.5 10.0 3.5 5.7 4.5 38.5 4.5 4.0 Green Ext Time (p_c), s 0.0 4.8 0.0 0.3 0.0 14.2 0.0 0.1 Intersection Summary HCM 7th Control Delay, s/veh 18.7 HCM 7th LOS B Page 276 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 1B PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 610 1110 780 180 150 v/c Ratio 0.42 0.26 0.61 0.73 0.57 0.37 Control Delay (s/veh)42.2 5.0 16.2 8.5 41.4 9.2 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)42.2 5.0 16.2 8.5 41.4 9.2 Queue Length 50th (ft)50 50 203 45 89 0 Queue Length 95th (ft)109 86 334 221 173 52 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 150 300 Base Capacity (vph)498 3077 2319 1190 498 552 Starvation Cap Reductn 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.20 0.20 0.48 0.66 0.36 0.27 Intersection Summary Page 277 of 349 Queues 6: Elks Lane & Prado Rd Alt 1B PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)50 710 10 1820 30 40 50 70 v/c Ratio 0.35 0.27 0.09 0.78 0.23 0.26 0.35 0.37 Control Delay (s/veh)52.5 6.7 49.5 20.2 50.4 33.0 52.5 21.5 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)52.5 6.7 49.5 20.2 50.4 33.0 52.5 21.5 Queue Length 50th (ft)32 79 6 529 19 13 32 6 Queue Length 95th (ft)73 173 25 #816 51 48 73 50 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)180 2621 180 2327 180 452 180 456 Starvation Cap Reductn 0 0 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.28 0.27 0.06 0.78 0.17 0.09 0.28 0.15 Intersection Summary # 95th percentile volume exceeds capacity, queue may be longer. Queue shown is maximum after two cycles. Page 278 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2A AM PEAK HOUR Page 279 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 2A AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 950 0 0 420 350 240 0 300 0 0 0 Future Volume (veh/h)100 950 0 0 420 350 240 0 300 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.95 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 950 0 0 420 350 240 0 300 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 143 1098 0 0 792 637 411 0 366 Arrive On Green 0.08 0.60 0.00 0.00 0.43 0.43 0.23 0.00 0.23 Sat Flow, veh/h 1753 1841 0 0 1841 1480 1753 0 1560 Grp Volume(v), veh/h 100 950 0 0 420 350 240 0 300 Grp Sat Flow(s),veh/h/ln 1753 1841 0 0 1841 1480 1753 0 1560 Q Serve(g_s), s 3.3 25.5 0.0 0.0 10.0 10.4 7.2 0.0 10.8 Cycle Q Clear(g_c), s 3.3 25.5 0.0 0.0 10.0 10.4 7.2 0.0 10.8 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 143 1098 0 0 792 637 411 0 366 V/C Ratio(X)0.70 0.87 0.00 0.00 0.53 0.55 0.58 0.00 0.82 Avail Cap(c_a), veh/h 592 1555 0 0 1555 1250 592 0 527 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 26.5 10.0 0.0 0.0 12.4 12.6 20.1 0.0 21.5 Incr Delay (d2), s/veh 6.0 3.9 0.0 0.0 0.6 0.7 1.3 0.0 6.7 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.5 8.1 0.0 0.0 3.5 3.0 2.7 0.0 4.0 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 32.5 13.8 0.0 0.0 13.0 13.3 21.4 0.0 28.2 LnGrp LOS C B B B C C Approach Vol, veh/h 1050 770 540 Approach Delay, s/veh 15.6 13.1 25.2 Approach LOS B B C Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 40.3 9.8 30.5 18.9 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 27.5 5.3 12.4 12.8 Green Ext Time (p_c), s 7.8 0.2 4.3 1.1 Intersection Summary HCM 7th Control Delay, s/veh 17.0 HCM 7th LOS B Page 280 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)40 1170 40 20 730 20 10 5 5 40 20 30 Future Volume (veh/h)40 1170 40 20 730 20 10 5 5 40 20 30 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.95 1.00 0.95 1.00 0.96 1.00 0.97 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 40 1170 40 20 730 20 10 5 5 40 20 30 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 82 1586 54 49 1532 42 27 137 137 82 128 193 Arrive On Green 0.05 0.46 0.46 0.03 0.44 0.44 0.02 0.17 0.17 0.05 0.20 0.20 Sat Flow, veh/h 1753 3443 118 1753 3471 95 1753 828 828 1753 651 977 Grp Volume(v), veh/h 40 594 616 20 368 382 10 0 10 40 0 50 Grp Sat Flow(s),veh/h/ln 1753 1749 1812 1753 1749 1818 1753 0 1655 1753 0 1629 Q Serve(g_s), s 1.5 18.5 18.6 0.8 9.9 9.9 0.4 0.0 0.3 1.5 0.0 1.7 Cycle Q Clear(g_c), s 1.5 18.5 18.6 0.8 9.9 9.9 0.4 0.0 0.3 1.5 0.0 1.7 Prop In Lane 1.00 0.06 1.00 0.05 1.00 0.50 1.00 0.60 Lane Grp Cap(c), veh/h 82 806 835 49 772 802 27 0 274 82 0 321 V/C Ratio(X)0.48 0.74 0.74 0.41 0.48 0.48 0.38 0.00 0.04 0.48 0.00 0.16 Avail Cap(c_a), veh/h 262 1569 1626 262 1569 1631 262 0 619 262 0 609 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 31.1 14.7 14.7 32.0 13.2 13.2 32.6 0.0 23.4 31.1 0.0 22.2 Incr Delay (d2), s/veh 4.4 1.3 1.3 5.4 0.5 0.4 8.5 0.0 0.1 4.4 0.0 0.2 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 0.7 6.5 6.8 0.4 3.5 3.6 0.2 0.0 0.1 0.7 0.0 0.7 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 35.4 16.1 16.0 37.4 13.7 13.6 41.1 0.0 23.5 35.4 0.0 22.5 LnGrp LOS D B B D B B D C D C Approach Vol, veh/h 1250 770 20 90 Approach Delay, s/veh 16.7 14.3 32.3 28.2 Approach LOS B B C C Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 6.9 35.8 6.0 18.2 8.1 34.5 8.1 16.1 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.8 20.6 2.4 3.7 3.5 11.9 3.5 2.3 Green Ext Time (p_c), s 0.0 10.2 0.0 0.2 0.0 5.2 0.0 0.0 Intersection Summary HCM 7th Control Delay, s/veh 16.4 HCM 7th LOS B Alt 2A AM Page 281 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 950 420 350 240 300 v/c Ratio 0.39 0.86 0.54 0.43 0.59 0.60 Control Delay (s/veh)33.9 20.4 19.2 3.8 31.6 16.7 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)33.9 20.4 19.2 3.8 31.6 16.7 Queue Length 50th (ft)40 274 131 0 92 44 Queue Length 95th (ft)92 527 251 49 183 133 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 300 Base Capacity (vph)550 1778 1399 1174 550 613 Starvation Cap Reductn 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.18 0.53 0.30 0.30 0.44 0.49 Intersection Summary Alt 2A AM Page 282 of 349 Queues 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)40 1210 20 750 10 10 40 50 v/c Ratio 0.15 0.49 0.08 0.30 0.04 0.04 0.15 0.17 Control Delay (s/veh)30.6 9.4 31.9 8.0 32.9 26.4 30.6 19.5 Queue Delay 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)30.6 9.4 31.9 8.0 32.9 26.4 30.6 19.5 Queue Length 50th (ft)8 74 4 38 2 1 8 4 Queue Length 95th (ft)55 344 35 190 22 19 55 46 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)374 3144 374 3149 374 895 374 888 Starvation Cap Reductn 0 451 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.11 0.45 0.05 0.24 0.03 0.01 0.11 0.06 Intersection Summary Alt 2A AM Page 283 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2A PM PEAK HOUR Page 284 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 2A PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 600 0 0 910 780 180 0 150 0 0 0 Future Volume (veh/h)100 600 0 0 910 780 180 0 150 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.96 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 600 0 0 910 780 180 0 150 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 130 1347 0 0 1087 882 237 0 211 Arrive On Green 0.07 0.73 0.00 0.00 0.59 0.59 0.14 0.00 0.14 Sat Flow, veh/h 1753 1841 0 0 1841 1493 1753 0 1560 Grp Volume(v), veh/h 100 600 0 0 910 780 180 0 150 Grp Sat Flow(s),veh/h/ln 1753 1841 0 0 1841 1493 1753 0 1560 Q Serve(g_s), s 4.2 9.7 0.0 0.0 30.0 33.6 7.4 0.0 6.9 Cycle Q Clear(g_c), s 4.2 9.7 0.0 0.0 30.0 33.6 7.4 0.0 6.9 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 130 1347 0 0 1087 882 237 0 211 V/C Ratio(X)0.77 0.45 0.00 0.00 0.84 0.88 0.76 0.00 0.71 Avail Cap(c_a), veh/h 467 1347 0 0 1226 995 467 0 416 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 34.1 4.0 0.0 0.0 12.4 13.2 31.3 0.0 31.1 Incr Delay (d2), s/veh 9.0 0.2 0.0 0.0 4.8 8.8 5.0 0.0 4.4 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 2.0 2.3 0.0 0.0 11.2 11.0 3.2 0.0 2.7 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 43.1 4.2 0.0 0.0 17.2 22.0 36.2 0.0 35.5 LnGrp LOS D A B C D D Approach Vol, veh/h 700 1690 330 Approach Delay, s/veh 9.8 19.4 35.9 Approach LOS A B D Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 59.9 10.6 49.3 15.1 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 11.7 6.2 35.6 9.4 Green Ext Time (p_c), s 4.4 0.2 8.7 0.7 Intersection Summary HCM 7th Control Delay, s/veh 18.9 HCM 7th LOS B Page 285 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)50 690 10 10 1600 20 30 20 20 50 10 60 Future Volume (veh/h)50 690 10 10 1600 20 30 20 20 50 10 60 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.96 1.00 0.96 1.00 0.96 1.00 0.96 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 50 690 10 10 1600 20 30 20 20 50 10 60 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 82 2019 29 26 1910 24 61 123 123 82 36 214 Arrive On Green 0.05 0.57 0.57 0.01 0.54 0.54 0.03 0.15 0.15 0.05 0.16 0.16 Sat Flow, veh/h 1753 3526 51 1753 3535 44 1753 826 826 1753 220 1322 Grp Volume(v), veh/h 50 342 358 10 791 829 30 0 40 50 0 70 Grp Sat Flow(s),veh/h/ln 1753 1749 1829 1753 1749 1830 1753 0 1651 1753 0 1543 Q Serve(g_s), s 2.6 9.6 9.6 0.5 35.1 35.2 1.6 0.0 2.0 2.6 0.0 3.7 Cycle Q Clear(g_c), s 2.6 9.6 9.6 0.5 35.1 35.2 1.6 0.0 2.0 2.6 0.0 3.7 Prop In Lane 1.00 0.03 1.00 0.02 1.00 0.50 1.00 0.86 Lane Grp Cap(c), veh/h 82 1001 1047 26 945 989 61 0 247 82 0 249 V/C Ratio(X)0.61 0.34 0.34 0.39 0.84 0.84 0.49 0.00 0.16 0.61 0.00 0.28 Avail Cap(c_a), veh/h 190 1135 1187 190 1135 1188 190 0 446 190 0 417 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 43.2 10.5 10.5 45.1 17.8 17.9 43.8 0.0 34.3 43.2 0.0 34.0 Incr Delay (d2), s/veh 7.0 0.2 0.2 9.3 4.8 4.7 6.0 0.0 0.3 7.0 0.0 0.6 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.3 3.4 3.6 0.3 13.8 14.5 0.8 0.0 0.8 1.3 0.0 1.4 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 50.3 10.7 10.7 54.4 22.6 22.5 49.8 0.0 34.6 50.3 0.0 34.7 LnGrp LOS D B B D C C D C D C Approach Vol, veh/h 750 1630 70 120 Approach Delay, s/veh 13.3 22.8 41.1 41.2 Approach LOS B C D D Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 6.4 57.9 8.2 19.9 9.3 55.0 9.3 18.8 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.5 11.6 3.6 5.7 4.6 37.2 4.6 4.0 Green Ext Time (p_c), s 0.0 4.8 0.0 0.3 0.0 12.7 0.0 0.1 Intersection Summary HCM 7th Control Delay, s/veh 21.4 HCM 7th LOS C Alt 2A PM Page 286 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 600 910 780 180 150 v/c Ratio 0.49 0.45 0.86 0.72 0.65 0.40 Control Delay (s/veh)46.3 6.7 29.1 8.0 46.9 9.4 Queue Delay 0.0 0.0 0.6 0.0 0.0 0.0 Total Delay (s/veh)46.3 6.7 29.7 8.0 46.9 9.4 Queue Length 50th (ft)54 115 429 44 97 0 Queue Length 95th (ft)109 216 #844 231 173 52 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 300 Base Capacity (vph)401 1552 1058 1085 401 473 Starvation Cap Reductn 0 0 24 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.25 0.39 0.88 0.72 0.45 0.32 Intersection Summary # 95th percentile volume exceeds capacity, queue may be longer. Queue shown is maximum after two cycles. Alt 2A PM Page 287 of 349 Queues 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)50 700 10 1620 30 40 50 70 v/c Ratio 0.30 0.27 0.07 0.71 0.20 0.23 0.30 0.34 Control Delay (s/veh)50.1 6.9 49.1 17.9 49.0 32.1 50.1 20.4 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)50.1 6.9 49.1 17.9 49.0 32.1 50.1 20.4 Queue Length 50th (ft)32 77 6 420 19 13 32 6 Queue Length 95th (ft)73 171 25 603 51 48 73 51 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)217 2598 217 2389 217 532 217 522 Starvation Cap Reductn 0 0 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.23 0.27 0.05 0.68 0.14 0.08 0.23 0.13 Intersection Summary Alt 2A PM Page 288 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2B AM PEAK HOUR Page 289 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 2B AM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 950 0 0 420 350 240 0 300 0 0 0 Future Volume (veh/h)100 950 0 0 420 350 240 0 300 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.95 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 950 0 0 420 350 240 0 300 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 143 1098 0 0 792 637 411 0 366 Arrive On Green 0.08 0.60 0.00 0.00 0.43 0.43 0.23 0.00 0.23 Sat Flow, veh/h 1753 1841 0 0 1841 1480 1753 0 1560 Grp Volume(v), veh/h 100 950 0 0 420 350 240 0 300 Grp Sat Flow(s),veh/h/ln 1753 1841 0 0 1841 1480 1753 0 1560 Q Serve(g_s), s 3.3 25.5 0.0 0.0 10.0 10.4 7.2 0.0 10.8 Cycle Q Clear(g_c), s 3.3 25.5 0.0 0.0 10.0 10.4 7.2 0.0 10.8 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 143 1098 0 0 792 637 411 0 366 V/C Ratio(X)0.70 0.87 0.00 0.00 0.53 0.55 0.58 0.00 0.82 Avail Cap(c_a), veh/h 592 1555 0 0 1555 1250 592 0 527 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 26.5 10.0 0.0 0.0 12.4 12.6 20.1 0.0 21.5 Incr Delay (d2), s/veh 6.0 3.9 0.0 0.0 0.6 0.7 1.3 0.0 6.7 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.5 8.1 0.0 0.0 3.5 3.0 2.7 0.0 4.0 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 32.5 13.8 0.0 0.0 13.0 13.3 21.4 0.0 28.2 LnGrp LOS C B B B C C Approach Vol, veh/h 1050 770 540 Approach Delay, s/veh 15.6 13.1 25.2 Approach LOS B B C Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 40.3 9.8 30.5 18.9 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 27.5 5.3 12.4 12.8 Green Ext Time (p_c), s 7.8 0.2 4.3 1.1 Intersection Summary HCM 7th Control Delay, s/veh 17.0 HCM 7th LOS B Page 290 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)40 1170 40 20 730 20 10 5 5 40 20 30 Future Volume (veh/h)40 1170 40 20 730 20 10 5 5 40 20 30 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.95 1.00 0.95 1.00 0.96 1.00 0.97 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 40 1170 40 20 730 20 10 5 5 40 20 30 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 82 1586 54 49 1532 42 27 137 137 82 128 193 Arrive On Green 0.05 0.46 0.46 0.03 0.44 0.44 0.02 0.17 0.17 0.05 0.20 0.20 Sat Flow, veh/h 1753 3443 118 1753 3471 95 1753 828 828 1753 651 977 Grp Volume(v), veh/h 40 594 616 20 368 382 10 0 10 40 0 50 Grp Sat Flow(s),veh/h/ln 1753 1749 1812 1753 1749 1818 1753 0 1655 1753 0 1629 Q Serve(g_s), s 1.5 18.5 18.6 0.8 9.9 9.9 0.4 0.0 0.3 1.5 0.0 1.7 Cycle Q Clear(g_c), s 1.5 18.5 18.6 0.8 9.9 9.9 0.4 0.0 0.3 1.5 0.0 1.7 Prop In Lane 1.00 0.06 1.00 0.05 1.00 0.50 1.00 0.60 Lane Grp Cap(c), veh/h 82 806 835 49 772 802 27 0 274 82 0 321 V/C Ratio(X)0.48 0.74 0.74 0.41 0.48 0.48 0.38 0.00 0.04 0.48 0.00 0.16 Avail Cap(c_a), veh/h 262 1569 1626 262 1569 1631 262 0 619 262 0 609 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 31.1 14.7 14.7 32.0 13.2 13.2 32.6 0.0 23.4 31.1 0.0 22.2 Incr Delay (d2), s/veh 4.4 1.3 1.3 5.4 0.5 0.4 8.5 0.0 0.1 4.4 0.0 0.2 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 0.7 6.5 6.8 0.4 3.5 3.6 0.2 0.0 0.1 0.7 0.0 0.7 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 35.4 16.1 16.0 37.4 13.7 13.6 41.1 0.0 23.5 35.4 0.0 22.5 LnGrp LOS D B B D B B D C D C Approach Vol, veh/h 1250 770 20 90 Approach Delay, s/veh 16.7 14.3 32.3 28.2 Approach LOS B B C C Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 6.9 35.8 6.0 18.2 8.1 34.5 8.1 16.1 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.8 20.6 2.4 3.7 3.5 11.9 3.5 2.3 Green Ext Time (p_c), s 0.0 10.2 0.0 0.2 0.0 5.2 0.0 0.0 Intersection Summary HCM 7th Control Delay, s/veh 16.4 HCM 7th LOS B Alt 2B AM Page 291 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 950 420 350 240 300 v/c Ratio 0.39 0.86 0.54 0.42 0.59 0.60 Control Delay (s/veh)33.9 20.4 19.2 3.7 31.6 16.7 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)33.9 20.4 19.2 3.7 31.6 16.7 Queue Length 50th (ft)40 274 131 0 92 44 Queue Length 95th (ft)92 527 251 49 183 133 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 300 Base Capacity (vph)550 1778 1399 1213 550 613 Starvation Cap Reductn 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.18 0.53 0.30 0.29 0.44 0.49 Intersection Summary Alt 2B AM Page 292 of 349 Queues 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)40 1210 20 750 10 10 40 50 v/c Ratio 0.15 0.49 0.08 0.30 0.04 0.04 0.15 0.17 Control Delay (s/veh)30.6 9.4 31.9 8.0 32.9 26.4 30.6 19.5 Queue Delay 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)30.6 9.4 31.9 8.0 32.9 26.4 30.6 19.5 Queue Length 50th (ft)8 74 4 38 2 1 8 4 Queue Length 95th (ft)55 344 35 190 22 19 55 46 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)374 3144 374 3149 374 895 374 888 Starvation Cap Reductn 0 451 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.11 0.45 0.05 0.24 0.03 0.01 0.11 0.06 Intersection Summary Alt 2B AM Page 293 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2B PM PEAK HOUR Page 294 of 349 HCM 7th Signalized Intersection Summary 3: US 101 NB Off/US 101 NB On & Prado Rd Alt 2B PM City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 2 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)100 600 0 0 910 780 180 0 150 0 0 0 Future Volume (veh/h)100 600 0 0 910 780 180 0 150 0 0 0 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 1.00 1.00 0.96 1.00 1.00 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No Adj Sat Flow, veh/h/ln 1841 1841 0 0 1841 1841 1841 0 1841 Adj Flow Rate, veh/h 100 600 0 0 910 780 180 0 150 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 0 0 4 4 4 0 4 Cap, veh/h 130 1347 0 0 1087 882 237 0 211 Arrive On Green 0.07 0.73 0.00 0.00 0.59 0.59 0.14 0.00 0.14 Sat Flow, veh/h 1753 1841 0 0 1841 1493 1753 0 1560 Grp Volume(v), veh/h 100 600 0 0 910 780 180 0 150 Grp Sat Flow(s),veh/h/ln 1753 1841 0 0 1841 1493 1753 0 1560 Q Serve(g_s), s 4.2 9.7 0.0 0.0 30.0 33.6 7.4 0.0 6.9 Cycle Q Clear(g_c), s 4.2 9.7 0.0 0.0 30.0 33.6 7.4 0.0 6.9 Prop In Lane 1.00 0.00 0.00 1.00 1.00 1.00 Lane Grp Cap(c), veh/h 130 1347 0 0 1087 882 237 0 211 V/C Ratio(X)0.77 0.45 0.00 0.00 0.84 0.88 0.76 0.00 0.71 Avail Cap(c_a), veh/h 467 1347 0 0 1226 995 467 0 416 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 0.00 0.00 1.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 34.1 4.0 0.0 0.0 12.4 13.2 31.3 0.0 31.1 Incr Delay (d2), s/veh 9.0 0.2 0.0 0.0 4.8 8.8 5.0 0.0 4.4 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 2.0 2.3 0.0 0.0 11.2 11.0 3.2 0.0 2.7 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 43.1 4.2 0.0 0.0 17.2 22.0 36.2 0.0 35.5 LnGrp LOS D A B C D D Approach Vol, veh/h 700 1690 330 Approach Delay, s/veh 9.8 19.4 35.9 Approach LOS A B D Timer - Assigned Phs 2 5 6 8 Phs Duration (G+Y+Rc), s 59.9 10.6 49.3 15.1 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 50.0 20.0 50.0 20.0 Max Q Clear Time (g_c+I1), s 11.7 6.2 35.6 9.4 Green Ext Time (p_c), s 4.4 0.2 8.7 0.7 Intersection Summary HCM 7th Control Delay, s/veh 18.9 HCM 7th LOS B Page 295 of 349 HCM 7th Signalized Intersection Summary 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 4 Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR Lane Configurations Traffic Volume (veh/h)50 690 10 10 1600 20 30 20 20 50 10 60 Future Volume (veh/h)50 690 10 10 1600 20 30 20 20 50 10 60 Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0 0 0 0 Lane Width Adj.1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ped-Bike Adj(A_pbT)1.00 0.96 1.00 0.96 1.00 0.96 1.00 0.96 Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Work Zone On Approach No No No No Adj Sat Flow, veh/h/ln 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 1841 Adj Flow Rate, veh/h 50 690 10 10 1600 20 30 20 20 50 10 60 Peak Hour Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Percent Heavy Veh, %4 4 4 4 4 4 4 4 4 4 4 4 Cap, veh/h 82 2019 29 26 1910 24 61 123 123 82 36 214 Arrive On Green 0.05 0.57 0.57 0.01 0.54 0.54 0.03 0.15 0.15 0.05 0.16 0.16 Sat Flow, veh/h 1753 3526 51 1753 3535 44 1753 826 826 1753 220 1322 Grp Volume(v), veh/h 50 342 358 10 791 829 30 0 40 50 0 70 Grp Sat Flow(s),veh/h/ln 1753 1749 1829 1753 1749 1830 1753 0 1651 1753 0 1543 Q Serve(g_s), s 2.6 9.6 9.6 0.5 35.1 35.2 1.6 0.0 2.0 2.6 0.0 3.7 Cycle Q Clear(g_c), s 2.6 9.6 9.6 0.5 35.1 35.2 1.6 0.0 2.0 2.6 0.0 3.7 Prop In Lane 1.00 0.03 1.00 0.02 1.00 0.50 1.00 0.86 Lane Grp Cap(c), veh/h 82 1001 1047 26 945 989 61 0 247 82 0 249 V/C Ratio(X)0.61 0.34 0.34 0.39 0.84 0.84 0.49 0.00 0.16 0.61 0.00 0.28 Avail Cap(c_a), veh/h 190 1135 1187 190 1135 1188 190 0 446 190 0 417 HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Upstream Filter(I)1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.00 1.00 1.00 0.00 1.00 Uniform Delay (d), s/veh 43.2 10.5 10.5 45.1 17.8 17.9 43.8 0.0 34.3 43.2 0.0 34.0 Incr Delay (d2), s/veh 7.0 0.2 0.2 9.3 4.8 4.7 6.0 0.0 0.3 7.0 0.0 0.6 Initial Q Delay(d3), s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 %ile BackOfQ(50%),veh/ln 1.3 3.4 3.6 0.3 13.8 14.5 0.8 0.0 0.8 1.3 0.0 1.4 Unsig. Movement Delay, s/veh LnGrp Delay(d), s/veh 50.3 10.7 10.7 54.4 22.6 22.5 49.8 0.0 34.6 50.3 0.0 34.7 LnGrp LOS D B B D C C D C D C Approach Vol, veh/h 750 1630 70 120 Approach Delay, s/veh 13.3 22.8 41.1 41.2 Approach LOS B C D D Timer - Assigned Phs 1 2 3 4 5 6 7 8 Phs Duration (G+Y+Rc), s 6.4 57.9 8.2 19.9 9.3 55.0 9.3 18.8 Change Period (Y+Rc), s 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Max Green Setting (Gmax), s 10.0 60.0 10.0 25.0 10.0 60.0 10.0 25.0 Max Q Clear Time (g_c+I1), s 2.5 11.6 3.6 5.7 4.6 37.2 4.6 4.0 Green Ext Time (p_c), s 0.0 4.8 0.0 0.3 0.0 12.7 0.0 0.1 Intersection Summary HCM 7th Control Delay, s/veh 21.4 HCM 7th LOS C Alt 2B PM Page 296 of 349 Queues 3: US 101 NB Off/US 101 NB On & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 1 Lane Group EBL EBT WBT WBR NBL NBR Lane Group Flow (vph)100 600 910 780 180 150 v/c Ratio 0.49 0.45 0.86 0.70 0.65 0.40 Control Delay (s/veh)46.3 6.7 29.1 7.4 46.9 9.4 Queue Delay 0.0 0.0 0.6 0.0 0.0 0.0 Total Delay (s/veh)46.3 6.7 29.7 7.4 46.9 9.4 Queue Length 50th (ft)54 115 429 43 97 0 Queue Length 95th (ft)109 216 #844 216 173 52 Internal Link Dist (ft)786 602 Turn Bay Length (ft)150 300 Base Capacity (vph)401 1552 1058 1115 401 473 Starvation Cap Reductn 0 0 24 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 Reduced v/c Ratio 0.25 0.39 0.88 0.70 0.45 0.32 Intersection Summary # 95th percentile volume exceeds capacity, queue may be longer. Queue shown is maximum after two cycles. Alt 2B PM Page 297 of 349 Queues 6: Elks Lane & Prado Rd City of SLO -US101 Prado Road Interchange Prado Rd.syn DKS Associates Page 3 Lane Group EBL EBT WBL WBT NBL NBT SBL SBT Lane Group Flow (vph)50 700 10 1620 30 40 50 70 v/c Ratio 0.30 0.27 0.07 0.71 0.20 0.23 0.30 0.34 Control Delay (s/veh)50.1 6.9 49.1 17.9 49.0 32.1 50.1 20.4 Queue Delay 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Total Delay (s/veh)50.1 6.9 49.1 17.9 49.0 32.1 50.1 20.4 Queue Length 50th (ft)32 77 6 420 19 13 32 6 Queue Length 95th (ft)73 171 25 603 51 48 73 51 Internal Link Dist (ft)602 903 272 534 Turn Bay Length (ft)100 100 100 100 Base Capacity (vph)217 2598 217 2389 217 532 217 522 Starvation Cap Reductn 0 0 0 0 0 0 0 0 Spillback Cap Reductn 0 0 0 0 0 0 0 0 Storage Cap Reductn 0 0 0 0 0 0 0 0 Reduced v/c Ratio 0.23 0.27 0.05 0.68 0.14 0.08 0.23 0.13 Intersection Summary Alt 2B PM Page 298 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 3 AM PEAK HOUR Page 299 of 349 SITE LAYOUT Site: [1 (3)] Single lane AM -NBR lane (US 101 NB Ramps) New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Layout pictures are schematic functional drawings reflecting input data. They are not design drawings. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Created: Monday, August 18, 2025 12:23:56 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 300 of 349 MOVEMENT SUMMARY Site: [1 (3)] Single lane AM -NBR lane (US 101 NB Ramps) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Vehicle Movement Performance Demand Flows Arrival Flows 95% Back Of QueueMov ID Turn Mov Class Deg. Satn Aver. Delay Level of Service Prop. Qued Eff. Stop Rate Number of Cycles to Depart Aver. Speed [ Total HV ][ Total HV ][ Veh.Dist ] veh/h %veh/h %v/c sec veh ft mph South: US 101 NB OFf 3 L2 All MCs 240 4.0 240 4.0 0.511 17.7 LOS C 2.5 63.3 0.78 0.90 1.23 26.1 8 T1 All MCs 1 4.0 1 4.0 0.511 20.4 LOS C 2.5 63.3 0.78 0.90 1.23 28.0 18 R2 All MCs 300 4.0 300 4.0 0.636 22.9 LOS C 3.7 94.6 0.82 1.01 1.51 25.8 Approach 541 4.0 541 4.0 0.636 20.6 LOS C 3.7 94.6 0.80 0.96 1.39 25.9 East: Prado Road 6 T1 All MCs 420 4.0 420 4.0 0.432 8.6 LOS A 2.2 57.4 0.57 0.40 0.58 29.1 16 R2 All MCs 350 4.0 350 4.0 0.217 3.8 LOS A 0.0 0.0 0.00 0.00 0.00 32.7 Approach 770 4.0 770 4.0 0.432 6.4 LOS A 2.2 57.4 0.31 0.22 0.31 30.6 West: Prado Road 5 L2 All MCs 100 4.0 100 4.0 0.789 9.4 LOS A 0.0 0.0 0.00 0.00 0.00 34.2 2 T1 All MCs 950 4.0 950 4.0 0.789 6.7 LOS A 0.0 0.0 0.00 0.00 0.00 32.5 Approach 1050 4.0 1050 4.0 0.789 6.9 LOS A 0.0 0.0 0.00 0.00 0.00 32.6 All Vehicles 2361 4.0 2361 4.0 0.789 9.9 LOS A 3.7 94.6 0.29 0.29 0.42 30.2 Site Level of Service (LOS) Method: Delay & v/c (HCM 6). Site LOS Method is specified in the Parameter Settings dialog (Options tab). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement. LOS F will result if v/c >1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 6). Roundabout Capacity Model: US HCM 6. Delay Model: HCM Delay Formula (Stopline Delay: Geometric Delay is not included). Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. Arrival Flows used in performance calculations are adjusted to include any Initial Queued Demand and Upstream Capacity Constraint effects. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Processed: Monday,June 23, 2025 11:29:14 AM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 301 of 349 QUEUE ANALYSIS Site: [1 (3)] Single lane AM -NBR lane (US 101 NB Ramps) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Lane Queues (Distance) Lane Number Contin. Lane Deg. Satn Prog. Factor (Queue) Overflow Queue (ft) Back of Queue (ft) Queue at Start of Gap (ft) Cycle-Average Queue (ft) Queue Storage Ratio Prob. Block. Prob. SL Ov. Ov. Lane No. v/c Av.95%Av.95%Av.95%Av.95%%% South: US 101 NB OFf Lane 1 0.511 1.000 7.1 25.5 63.3 23.2 57.6 30.6 55.5 0.02 0.04 0.0 NA NA Lane 2 0.636 1.000 13.6 38.0 94.6 33.7 83.7 49.2 89.3 0.13 0.32 NA 0.0 1 Approach 0.636 38.0 94.6 33.7 83.7 49.2 89.3 0.02 0.04 East: Prado Road Lane 1 0.432 1.000 0.2 23.1 57.4 15.9 39.5 25.8 46.8 0.01 0.04 0.0 NA NA Lane 2 Y 0.217 1.000 0.0 0.0 0.0 0.0 0.0 0.2 0.3 0.00 0.00 0.0 NA NA Approach 0.432 23.1 57.4 15.9 39.5 25.8 46.8 0.01 0.04 West: Prado Road Lane 1 0.789 1.000 0.0 0.0 0.0 0.0 0.0 50.1 90.8 0.00 0.00 0.0 NA NA Approach 0.789 0.0 0.0 0.0 0.0 50.1 90.8 0.00 0.00 Intersection 0.789 38.0 94.6 33.7 83.7 50.1 90.8 0.02 0.04 Roundabout Capacity Model: US HCM 6. Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. Short Lanes are not included in determining Queue Storage Ratios. Page 302 of 349 SITE LAYOUT Site: [2 (2)] Dual lane EB AM (Elks) New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Layout pictures are schematic functional drawings reflecting input data. They are not design drawings. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Created: Monday, August 18, 2025 12:27:53 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 303 of 349 MOVEMENT SUMMARY Site: [2 (2)] Dual lane EB AM (Elks) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Vehicle Movement Performance Demand Flows Arrival Flows 95% Back Of QueueMov ID Turn Mov Class Deg. Satn Aver. Delay Level of Service Prop. Qued Eff. Stop Rate Number of Cycles to Depart Aver. Speed [ Total HV ][ Total HV ][ Veh.Dist ] veh/h %veh/h %v/c sec veh ft mph South: Elks Lane 3 L2 All MCs 10 4.0 10 4.0 0.049 9.5 LOS A 0.1 3.5 0.68 0.68 0.68 24.3 8 T1 All MCs 5 4.0 5 4.0 0.049 9.5 LOS A 0.1 3.5 0.68 0.68 0.68 24.6 18 R2 All MCs 5 4.0 5 4.0 0.049 9.5 LOS A 0.1 3.5 0.68 0.68 0.68 24.5 Approach 20 4.0 20 4.0 0.049 9.5 LOS A 0.1 3.5 0.68 0.68 0.68 24.4 East: Prado Road 1 L2 All MCs 20 4.0 20 4.0 0.298 5.3 LOS A 1.5 39.3 0.20 0.07 0.20 26.0 6 T1 All MCs 730 4.0 730 4.0 0.298 5.3 LOS A 1.5 39.3 0.20 0.07 0.20 30.3 16 R2 All MCs 20 4.0 20 4.0 0.298 5.3 LOS A 1.5 39.3 0.20 0.07 0.20 30.1 Approach 770 4.0 770 4.0 0.298 5.3 LOS A 1.5 39.3 0.20 0.07 0.20 30.2 North: Elks Lane 7 L2 All MCs 40 4.0 40 4.0 0.136 6.9 LOS A 0.4 11.5 0.57 0.53 0.57 28.5 4 T1 All MCs 20 4.0 20 4.0 0.136 6.9 LOS A 0.4 11.5 0.57 0.53 0.57 25.2 14 R2 All MCs 30 4.0 30 4.0 0.136 6.9 LOS A 0.4 11.5 0.57 0.53 0.57 28.8 Approach 90 4.0 90 4.0 0.136 6.9 LOS A 0.4 11.5 0.57 0.53 0.57 27.8 West: Prado Road 5 L2 All MCs 40 4.0 40 4.0 0.495 7.8 LOS A 3.4 86.5 0.33 0.13 0.33 28.8 2 T1 All MCs 1170 4.0 1170 4.0 0.495 7.8 LOS A 3.4 86.5 0.33 0.13 0.33 29.3 12 R2 All MCs 40 4.0 40 4.0 0.495 7.8 LOS A 3.4 86.5 0.33 0.13 0.33 25.4 Approach 1250 4.0 1250 4.0 0.495 7.8 LOS A 3.4 86.5 0.33 0.13 0.33 29.2 All Vehicles 2130 4.0 2130 4.0 0.495 6.8 LOS A 3.4 86.5 0.30 0.13 0.30 29.4 Site Level of Service (LOS) Method: Delay & v/c (HCM 6). Site LOS Method is specified in the Parameter Settings dialog (Options tab). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement. LOS F will result if v/c >1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 6). Roundabout Capacity Model: US HCM 6. Delay Model: HCM Delay Formula (Stopline Delay: Geometric Delay is not included). Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. Arrival Flows used in performance calculations are adjusted to include any Initial Queued Demand and Upstream Capacity Constraint effects. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Processed: Wednesday, July 23, 2025 6:36:19 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 304 of 349 QUEUE ANALYSIS Site: [2 (2)] Dual lane EB AM (Elks) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Lane Queues (Distance) Lane Number Contin. Lane Deg. Satn Prog. Factor (Queue) Overflow Queue (ft) Back of Queue (ft) Queue at Start of Gap (ft) Cycle-Average Queue (ft) Queue Storage Ratio Prob. Block. Prob. SL Ov. Ov. Lane No. v/c Av.95%Av.95%Av.95%Av.95%%% South: Elks Lane Lane 1 0.049 1.000 0.0 1.4 3.5 1.4 3.5 1.4 2.5 0.00 0.00 0.0 NA NA Approach 0.049 1.4 3.5 1.4 3.5 1.4 2.5 0.00 0.00 East: Prado Road Lane 1 0.298 1.000 0.0 15.8 39.3 11.4 28.2 14.5 26.3 0.01 0.02 0.0 NA NA Lane 2 0.298 1.000 0.0 15.8 39.3 11.4 28.2 14.5 26.3 0.01 0.02 0.0 NA NA Approach 0.298 15.8 39.3 11.4 28.2 14.5 26.3 0.01 0.02 North: Elks Lane Lane 1 0.136 1.000 0.0 4.6 11.5 4.3 10.7 4.5 8.1 0.00 0.01 0.0 NA NA Approach 0.136 4.6 11.5 4.3 10.7 4.5 8.1 0.00 0.01 West: Prado Road Lane 1 0.495 1.000 0.0 34.8 86.5 18.8 46.8 34.8 63.2 0.02 0.05 0.0 NA NA Lane 2 0.495 1.000 0.0 34.8 86.5 18.8 46.8 34.8 63.2 0.12 0.29 NA 0.0 1 Approach 0.495 34.8 86.5 18.8 46.8 34.8 63.2 0.02 0.05 Intersection 0.495 34.8 86.5 18.8 46.8 34.8 63.2 0.02 0.05 Roundabout Capacity Model: US HCM 6. Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. Short Lanes are not included in determining Queue Storage Ratios. Page 305 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 3 PM PEAK HOUR Page 306 of 349 SITE LAYOUT Site: [1 (4)] Single lane PM -NBR Lane (US 101 NB Ramps) New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Layout pictures are schematic functional drawings reflecting input data. They are not design drawings. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Created: Monday, August 18, 2025 12:29:26 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 307 of 349 MOVEMENT SUMMARY Site: [1 (4)] Single lane PM -NBR Lane (US 101 NB Ramps) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Vehicle Movement Performance Demand Flows Arrival Flows 95% Back Of QueueMov ID Turn Mov Class Deg. Satn Aver. Delay Level of Service Prop. Qued Eff. Stop Rate Number of Cycles to Depart Aver. Speed [ Total HV ][ Total HV ][ Veh.Dist ] veh/h %veh/h %v/c sec veh ft mph South: US 101 NB OFf 3 L2 All MCs 180 4.0 180 4.0 0.268 8.6 LOS A 1.0 26.2 0.63 0.56 0.63 29.1 8 T1 All MCs 1 4.0 1 4.0 0.268 11.6 LOS B 1.0 26.2 0.63 0.56 0.63 31.5 18 R2 All MCs 150 4.0 150 4.0 0.222 7.9 LOS A 0.8 21.1 0.61 0.55 0.61 31.2 Approach 331 4.0 331 4.0 0.268 8.3 LOS A 1.0 26.2 0.62 0.56 0.62 30.0 East: Prado Road 6 T1 All MCs 910 4.0 910 4.0 0.882 25.7 LOS D 26.3 677.3 1.00 1.37 2.25 23.8 16 R2 All MCs 780 4.0 780 4.0 0.484 6.5 LOS A 0.0 0.0 0.00 0.00 0.00 32.6 Approach 1690 4.0 1690 4.0 0.882 16.8 LOS C 26.3 677.3 0.54 0.74 1.21 27.1 West: Prado Road 5 L2 All MCs 100 4.0 100 4.0 0.526 8.4 LOS A 0.0 0.0 0.00 0.00 0.00 34.1 2 T1 All MCs 600 4.0 600 4.0 0.526 5.3 LOS A 0.0 0.0 0.00 0.00 0.00 32.4 Approach 700 4.0 700 4.0 0.526 5.8 LOS A 0.0 0.0 0.00 0.00 0.00 32.6 All Vehicles 2721 4.0 2721 4.0 0.882 13.0 LOS B 26.3 677.3 0.41 0.53 0.83 28.7 Site Level of Service (LOS) Method: Delay & v/c (HCM 6). Site LOS Method is specified in the Parameter Settings dialog (Options tab). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement. LOS F will result if v/c >1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 6). Roundabout Capacity Model: US HCM 6. Delay Model: HCM Delay Formula (Stopline Delay: Geometric Delay is not included). Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. Arrival Flows used in performance calculations are adjusted to include any Initial Queued Demand and Upstream Capacity Constraint effects. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Processed: Wednesday, July 23, 2025 6:46:27 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 308 of 349 QUEUE ANALYSIS Site: [1 (4)] Single lane PM -NBR Lane (US 101 NB Ramps) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Lane Queues (Distance) Lane Number Contin. Lane Deg. Satn Prog. Factor (Queue) Overflow Queue (ft) Back of Queue (ft) Queue at Start of Gap (ft) Cycle-Average Queue (ft) Queue Storage Ratio Prob. Block. Prob. SL Ov. Ov. Lane No. v/c Av.95%Av.95%Av.95%Av.95%%% South: US 101 NB OFf Lane 1 0.268 1.000 0.0 10.5 26.2 9.1 22.6 11.1 20.2 0.01 0.02 0.0 NA NA Lane 2 0.222 1.000 0.0 8.5 21.1 7.5 18.7 8.5 15.4 0.03 0.07 NA 0.0 1 Approach 0.268 10.5 26.2 9.1 22.6 11.1 20.2 0.01 0.02 East: Prado Road Lane 1 0.882 1.000 110.1 272.5 677.3 142.5 354.1 167.7 304.3 0.17 0.42 0.0 NA NA Lane 2 Y 0.484 1.000 0.0 0.0 0.0 0.0 0.0 1.4 2.5 0.00 0.00 0.0 NA NA Approach 0.882 272.5 677.3 142.5 354.1 167.7 304.3 0.17 0.42 West: Prado Road Lane 1 0.526 1.000 0.0 0.0 0.0 0.0 0.0 26.8 48.6 0.00 0.00 0.0 NA NA Approach 0.526 0.0 0.0 0.0 0.0 26.8 48.6 0.00 0.00 Intersection 0.882 272.5 677.3 142.5 354.1 167.7 304.3 0.17 0.42 Roundabout Capacity Model: US HCM 6. Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. Short Lanes are not included in determining Queue Storage Ratios. Page 309 of 349 SITE LAYOUT Site: [2 (4)] Dual lane EB PM (Elks) New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Layout pictures are schematic functional drawings reflecting input data. They are not design drawings. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Created: Monday, August 18, 2025 12:30:54 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 310 of 349 MOVEMENT SUMMARY Site: [2 (4)] Dual lane EB PM (Elks) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Vehicle Movement Performance Demand Flows Arrival Flows 95% Back Of QueueMov ID Turn Mov Class Deg. Satn Aver. Delay Level of Service Prop. Qued Eff. Stop Rate Number of Cycles to Depart Aver. Speed [ Total HV ][ Total HV ][ Veh.Dist ] veh/h %veh/h %v/c sec veh ft mph South: Elks Lane 3 L2 All MCs 30 4.0 30 4.0 0.109 6.8 LOS A 0.3 9.0 0.57 0.53 0.57 25.1 8 T1 All MCs 20 4.0 20 4.0 0.109 6.8 LOS A 0.3 9.0 0.57 0.53 0.57 25.4 18 R2 All MCs 20 4.0 20 4.0 0.109 6.8 LOS A 0.3 9.0 0.57 0.53 0.57 25.3 Approach 70 4.0 70 4.0 0.109 6.8 LOS A 0.3 9.0 0.57 0.53 0.57 25.2 East: Prado Road 1 L2 All MCs 10 4.0 10 4.0 0.659 11.0 LOS B 6.0 154.8 0.51 0.23 0.51 24.4 6 T1 All MCs 1600 4.0 1600 4.0 0.659 11.0 LOS B 6.0 154.8 0.51 0.23 0.51 28.2 16 R2 All MCs 20 4.0 20 4.0 0.659 11.0 LOS B 6.0 154.8 0.51 0.23 0.51 28.0 Approach 1630 4.0 1630 4.0 0.659 11.0 LOS B 6.0 154.8 0.51 0.23 0.51 28.2 North: Elks Lane 7 L2 All MCs 50 4.0 50 4.0 0.436 24.8 LOS C 1.4 35.4 0.85 0.94 1.16 23.3 4 T1 All MCs 10 4.0 10 4.0 0.436 24.8 LOS C 1.4 35.4 0.85 0.94 1.16 21.0 14 R2 All MCs 60 4.0 60 4.0 0.436 24.8 LOS C 1.4 35.4 0.85 0.94 1.16 23.4 Approach 120 4.0 120 4.0 0.436 24.8 LOS C 1.4 35.4 0.85 0.94 1.16 23.1 West: Prado Road 5 L2 All MCs 50 4.0 50 4.0 0.294 5.3 LOS A 1.5 38.4 0.23 0.09 0.23 29.6 2 T1 All MCs 690 4.0 690 4.0 0.294 5.3 LOS A 1.5 38.4 0.23 0.09 0.23 30.2 12 R2 All MCs 10 4.0 10 4.0 0.294 5.3 LOS A 1.5 38.4 0.23 0.09 0.23 26.2 Approach 750 4.0 750 4.0 0.294 5.3 LOS A 1.5 38.4 0.23 0.09 0.23 30.1 All Vehicles 2570 4.0 2570 4.0 0.659 9.9 LOS A 6.0 154.8 0.44 0.23 0.46 28.3 Site Level of Service (LOS) Method: Delay & v/c (HCM 6). Site LOS Method is specified in the Parameter Settings dialog (Options tab). Roundabout LOS Method: Same as Sign Control. Vehicle movement LOS values are based on average delay and v/c ratio (degree of saturation) per movement. LOS F will result if v/c >1 irrespective of movement delay value (does not apply for approaches and intersection). Intersection and Approach LOS values are based on average delay for all movements (v/c not used as specified in HCM 6). Roundabout Capacity Model: US HCM 6. Delay Model: HCM Delay Formula (Stopline Delay: Geometric Delay is not included). Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. HV (%) values are calculated for All Movement Classes of All Heavy Vehicle Model Designation. Arrival Flows used in performance calculations are adjusted to include any Initial Queued Demand and Upstream Capacity Constraint effects. SIDRA INTERSECTION 10.0 | Copyright © 2000-2025 Akcelik and Associates Pty Ltd | sidrasolutions.com Organisation: DKS ASSOCIATES | Licence: NETWORK / FLOATING | Processed: Wednesday, July 23, 2025 6:36:58 PM Project: L:\All-DKS\SAC\P\24000\900s\P24989-000 City of SLO -US101 Prado Road Interchange\12 Traffic Analysis\Sidra\2050 RABs.sipx Page 311 of 349 QUEUE ANALYSIS Site: [2 (4)] Dual lane EB PM (Elks) Output produced by SIDRA INTERSECTION Version: 10.0.5.217 New Site Site Category: (None) Roundabout Site Scenario: 1 | Local Volumes Lane Queues (Distance) Lane Number Contin. Lane Deg. Satn Prog. Factor (Queue) Overflow Queue (ft) Back of Queue (ft) Queue at Start of Gap (ft) Cycle-Average Queue (ft) Queue Storage Ratio Prob. Block. Prob. SL Ov. Ov. Lane No. v/c Av.95%Av.95%Av.95%Av.95%%% South: Elks Lane Lane 1 0.109 1.000 0.0 3.6 9.0 3.4 8.5 3.4 6.2 0.00 0.01 0.0 NA NA Approach 0.109 3.6 9.0 3.4 8.5 3.4 6.2 0.00 0.01 East: Prado Road Lane 1 0.659 1.000 0.0 62.3 154.8 25.0 62.0 64.3 116.7 0.04 0.10 0.0 NA NA Lane 2 0.659 1.000 0.0 62.3 154.8 25.0 62.0 64.3 116.7 0.04 0.10 0.0 NA NA Approach 0.659 62.3 154.8 25.0 62.0 64.3 116.7 0.04 0.10 North: Elks Lane Lane 1 0.436 1.000 2.8 14.2 35.4 14.2 35.3 21.3 38.7 0.01 0.02 0.0 NA NA Approach 0.436 14.2 35.4 14.2 35.3 21.3 38.7 0.01 0.02 West: Prado Road Lane 1 0.294 1.000 0.0 15.5 38.4 11.2 27.8 14.3 26.0 0.01 0.02 0.0 NA NA Lane 2 0.294 1.000 0.0 15.5 38.4 11.2 27.8 14.3 26.0 0.05 0.13 NA 0.0 1 Approach 0.294 15.5 38.4 11.2 27.8 14.3 26.0 0.01 0.02 Intersection 0.659 62.3 154.8 25.0 62.0 64.3 116.7 0.04 0.10 Roundabout Capacity Model: US HCM 6. Queue Model: SIDRA queue estimation methods are used for Back of Queue and Queue at Start of Gap. Gap-Acceptance Capacity Formula: Siegloch M1 implied by US HCM 6 Roundabout Capacity Model. Short Lanes are not included in determining Queue Storage Ratios. Page 312 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 SECTION 2: VISSIM RESULTS Page 313 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 NO BUILD AM PEAK HOUR Page 314 of 349 City of SLO - US101 Prado Road Interchange No Build AM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left - - Through 30 34 113% 0.7 8 A Right 310 308 99% 0.1 4 A U-Turn - - Total 340 342 101% 0.1 4 A Left 55 54 98% 0.1 6 A Through - - Right 15 14 93% 0.3 3 A U-Turn - - Total 70 68 97% 0.2 5 A Left - - Through - - Right - - U-Turn - - Total - - 0 Left - - Through 565 563 100% 0.1 30 D Right 15 15 100% 0.0 22 C U-Turn - - Total 580 578 100% 0.1 30 D 990 988 100% 0.1 19 C TABLE: AVERAGE DELAY Total US 101 Ramps / Prado Rd / Elks Ln NB SB EB WB DKS Associates 9/2/2025Page 315 of 349 City of SLO - US101 Prado Road Interchange No Build AM 20 (60) 225 (475) 40 (120) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd / Elks Ln DKS Associates 9/2/2025Page 316 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 NO BUILD PM PEAK HOUR Page 317 of 349 City of SLO - US101 Prado Road Interchange No Build PM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left - - Through 10 11 110% 0.3 7 A Right 125 123 98% 0.2 2 A U-Turn - - Total 135 134 99% 0.1 2 A Left 45 44 98% 0.1 6 A Through - - Right 25 23 92% 0.4 4 A U-Turn - - Total 70 67 96% 0.4 5 A Left - - Through - - Right - - U-Turn - - Total - - 0 Left - - Through 980 600 61% 13.5 267 F Right 30 19 63% 2.2 260 F U-Turn - - Total 1010 619 61% 13.7 267 F 1215 820 67% 12.4 202 F EB WB TABLE: AVERAGE DELAY Total US 101 Ramps / Prado Rd / Elks Ln NB SB DKS Associates 9/2/2025Page 318 of 349 City of SLO - US101 Prado Road Interchange No Build PM 20 (60) 1545 (1690) 10 (60) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd / Elks Ln DKS Associates 9/2/2025Page 319 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1A AM PEAK HOUR Page 320 of 349 City of SLO - US101 Prado Road Interchange Alternative 1A AM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 240 234 98% 0.4 34 C Through - - Right 300 305 102% 0.3 13 B U-Turn - - Total 540 539 100% 0.0 22 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 97 97% 0.3 34 C Through 1150 1146 100% 0.1 8 A Right - - U-Turn - - Total 1250 1243 99% 0.2 10 A Left - - Through 620 616 99% 0.2 13 B Right 350 353 101% 0.2 9 A U-Turn - - Total 970 969 100% 0.0 11 B 2760 2751 100% 0.2 13 B Left 10 11 110% 0.3 51 D Through 5 5 100% 0.0 33 C Right 5 4 80% 0.5 7 A U-Turn - - Total 20 20 100% 0.0 38 D Left 40 39 98% 0.2 47 D Through 20 20 100% 0.0 31 C Right 30 28 93% 0.4 11 B U-Turn - - Total 90 87 97% 0.3 32 C Left 40 36 90% 0.6 49 D Through 1370 1375 100% 0.1 13 B Right 40 40 100% 0.0 11 B U-Turn - - Total 1450 1451 100% 0.0 14 B Left 20 19 95% 0.2 47 D Through 930 930 100% 0.0 14 B Right 20 19 95% 0.2 12 B U-Turn - - Total 970 968 100% 0.1 14 B 2530 2526 100% 0.1 15 B TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB EB WB DKS Associates 8/18/2025Page 321 of 349 City of SLO - US101 Prado Road Interchange Alternative 1A AM 8 $ 9 60 (130)=<85 (245) 140 (235)"!115 (240) ?> : # ; 130 (235)85 (185) 25 (65) 30 (80) 8 $ 9 30 (80)=< 265 (470)"!185 (355) ?>15 (45) : # ; 10 (35) 5 (20) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 322 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1A PM PEAK HOUR Page 323 of 349 City of SLO - US101 Prado Road Interchange Alternative 1A PM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 180 177 98% 0.2 37 D Through - - Right 150 152 101% 0.2 7 A U-Turn - - Total 330 329 100% 0.1 23 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 95 95% 0.5 39 D Through 610 612 100% 0.1 5 A Right - - U-Turn - - Total 710 707 100% 0.1 9 A Left - - Through 1110 1107 100% 0.1 16 B Right 780 788 101% 0.3 29 C U-Turn - - Total 1890 1895 100% 0.1 21 C 2930 2931 100% 0.0 19 B Left 30 28 93% 0.4 53 D Through 20 22 110% 0.4 41 D Right 20 19 95% 0.2 11 B U-Turn - - Total 70 69 99% 0.1 38 D Left 50 51 102% 0.1 49 D Through 10 11 110% 0.3 45 D Right 60 58 97% 0.3 22 C U-Turn - - Total 120 120 100% 0.0 36 D Left 50 50 100% 0.0 55 D Through 700 705 101% 0.2 10 A Right 10 8 80% 0.7 6 A U-Turn - - Total 760 763 100% 0.1 13 B Left 10 9 90% 0.3 64 E Through 1800 1799 100% 0.0 39 D Right 20 22 110% 0.4 38 D U-Turn - - Total 1830 1830 100% 0.0 39 D 2780 2782 100% 0.0 31 C TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB EB WB DKS Associates 8/18/2025Page 324 of 349 City of SLO - US101 Prado Road Interchange Alternative 1A PM 8 $ 9 65 (135)=<430 (725) 60 (115)"!310 (715) ?> : # ; 110 (210)35 (85) 35 (90) 40 (95) 8 $ 9 45 (105)=< 105 (240)"!665 (950) ?>10 (45) : # ; 25 (65) 20 (70) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 325 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1B AM PEAK HOUR Page 326 of 349 City of SLO - US101 Prado Road Interchange Alternative 1B AM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 240 235 98% 0.3 31 C Through - - Right 300 305 102% 0.3 13 B U-Turn - - Total 540 540 100% 0.0 21 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 97 97% 0.3 31 C Through 1150 1150 100% 0.0 8 A Right - - U-Turn - - Total 1250 1247 100% 0.1 10 B Left - - Through 620 613 99% 0.3 13 B Right 350 352 101% 0.1 3 A U-Turn - - Total 970 965 99% 0.2 9 A 2760 2752 100% 0.2 12 B Left 10 10 100% 0.0 51 D Through 5 5 100% 0.0 38 D Right 5 5 100% 0.0 10 B U-Turn - - Total 20 20 100% 0.0 38 D Left 40 39 98% 0.2 49 D Through 20 22 110% 0.4 36 D Right 30 28 93% 0.4 11 B U-Turn - - Total 90 89 99% 0.1 34 C Left 40 36 90% 0.6 47 D Through 1370 1373 100% 0.1 13 B Right 40 40 100% 0.0 11 B U-Turn - - Total 1450 1449 100% 0.0 14 B Left 20 19 95% 0.2 48 D Through 930 927 100% 0.1 13 B Right 20 18 90% 0.5 12 B U-Turn - - Total 970 964 99% 0.2 14 B 2530 2522 100% 0.2 15 B EB WB TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB DKS Associates 8/18/2025Page 327 of 349 City of SLO - US101 Prado Road Interchange Alternative 1B AM 8 $ 9 55 (135)=<30 (145) 135 (260)"!115 (260) ?> : # ; 120 (240)85 (190) 25 (75) 30 (85) 8 $ 9 30 (85)=< 255 (515)"!180 (355) ?>20 (60) : # ; 10 (40) 5 (25) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/20/2025Page 328 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 1B PM PEAK HOUR Page 329 of 349 City of SLO - US101 Prado Road Interchange Alternative 1B PM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 180 177 98% 0.2 33 C Through - - Right 150 152 101% 0.2 7 A U-Turn - - Total 330 329 100% 0.1 21 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 95 95% 0.5 34 C Through 610 613 100% 0.1 5 A Right - - U-Turn - - Total 710 708 100% 0.1 9 A Left - - Through 1110 1110 100% 0.0 13 B Right 780 789 101% 0.3 7 A U-Turn - - Total 1890 1899 100% 0.2 10 B 2930 2936 100% 0.1 11 B Left 30 27 90% 0.6 53 D Through 20 22 110% 0.4 41 D Right 20 19 95% 0.2 11 B U-Turn - - Total 70 68 97% 0.2 37 D Left 50 52 104% 0.3 48 D Through 10 11 110% 0.3 40 D Right 60 59 98% 0.1 20 C U-Turn - - Total 120 122 102% 0.2 34 C Left 50 49 98% 0.1 55 D Through 700 704 101% 0.2 10 A Right 10 8 80% 0.7 7 A U-Turn - - Total 760 761 100% 0.0 12 B Left 10 8 80% 0.7 63 E Through 1800 1802 100% 0.0 32 C Right 20 22 110% 0.4 30 C U-Turn - - Total 1830 1832 100% 0.0 32 C 2780 2783 100% 0.1 27 C TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB EB WB DKS Associates 8/18/2025Page 330 of 349 City of SLO - US101 Prado Road Interchange Alternative 1B PM 8 $ 9 60 (135)=<115 (495) 60 (130)"!220 (545) ?> : # ; 95 (205)40 (95) 35 (90) 40 (90) 8 $ 9 40 (105)=< 105 (210)"!610 (945) ?>10 (45) : # ; 25 (70) 20 (70) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 331 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2A AM PEAK HOUR Page 332 of 349 City of SLO - US101 Prado Road Interchange Alternative 2A AM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 240 236 98% 0.3 37 D Through - - Right 300 305 102% 0.3 27 C U-Turn - - Total 540 541 100% 0.0 31 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 99 99% 0.1 42 D Through 950 949 100% 0.0 17 B Right - - U-Turn - - Total 1050 1048 100% 0.1 19 B Left - - Through 420 415 99% 0.2 16 B Right 350 350 100% 0.0 10 B U-Turn - - Total 770 765 99% 0.2 13 B 2360 2354 100% 0.1 20 B Left 10 10 100% 0.0 51 D Through 5 5 100% 0.0 41 D Right 5 5 100% 0.0 7 A U-Turn - - Total 20 20 100% 0.0 38 D Left 40 40 100% 0.0 46 D Through 20 21 105% 0.2 33 C Right 30 29 97% 0.2 9 A U-Turn - - Total 90 90 100% 0.0 31 C Left 40 37 93% 0.5 44 D Through 1170 1176 101% 0.2 12 B Right 40 39 98% 0.2 9 A U-Turn - - Total 1250 1252 100% 0.1 13 B Left 20 19 95% 0.2 40 D Through 730 731 100% 0.0 13 B Right 20 20 100% 0.0 10 A U-Turn - - Total 770 770 100% 0.0 13 B 2130 2132 100% 0.0 14 B EB WB TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB DKS Associates 8/18/2025Page 333 of 349 City of SLO - US101 Prado Road Interchange Alternative 2A AM 8 $ 9 75 (140)=<105 (295) 410 (865)"!160 (360) ?> : # ; 135 (255)140 (330) 25 (70) 30 (90) 8 $ 9 30 (80)=< 235 (585)"!150 (315) ?>20 (50) : # ; 10 (45) 5 (25) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 334 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2A PM PEAK HOUR Page 335 of 349 City of SLO - US101 Prado Road Interchange Alternative 2A PM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 180 178 99% 0.1 37 D Through - - Right 150 152 101% 0.2 9 A U-Turn - - Total 330 330 100% 0.0 24 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 96 96% 0.4 35 D Through 600 603 101% 0.1 7 A Right - - U-Turn - - Total 700 699 100% 0.0 11 B Left - - Through 910 901 99% 0.3 16 B Right 780 784 101% 0.1 27 C U-Turn - - Total 1690 1685 100% 0.1 21 C 2720 2714 100% 0.1 19 B Left 30 28 93% 0.4 53 D Through 20 21 105% 0.2 39 D Right 20 20 100% 0.0 10 B U-Turn - - Total 70 69 99% 0.1 36 D Left 50 52 104% 0.3 48 D Through 10 11 110% 0.3 46 D Right 60 58 97% 0.3 18 B U-Turn - - Total 120 121 101% 0.1 33 C Left 50 50 100% 0.0 58 E Through 690 694 101% 0.2 10 A Right 10 8 80% 0.7 7 A U-Turn - - Total 750 752 100% 0.1 13 B Left 10 8 80% 0.7 66 E Through 1600 1593 100% 0.2 30 C Right 20 19 95% 0.2 27 C U-Turn - - Total 1630 1620 99% 0.2 30 C 2570 2562 100% 0.2 26 C TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB EB WB DKS Associates 8/18/2025Page 336 of 349 City of SLO - US101 Prado Road Interchange Alternative 2A PM 8 $ 9 60 (135)=<460 (740) 130 (300)"!435 (740) ?> : # ; 105 (205)40 (105) 35 (95) 45 (90) 8 $ 9 45 (105)=< 100 (220)"!550 (945) ?>10 (45) : # ; 25 (65) 20 (65) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 337 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2B AM PEAK HOUR Page 338 of 349 City of SLO - US101 Prado Road Interchange Alternative 2B AM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 240 236 98% 0.3 36 D Through - - Right 300 304 101% 0.2 26 C U-Turn - - Total 540 540 100% 0.0 31 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 99 99% 0.1 42 D Through 950 947 100% 0.1 16 B Right - - U-Turn - - Total 1050 1046 100% 0.1 19 B Left - - Through 420 417 99% 0.1 16 B Right 350 352 101% 0.1 2 A U-Turn - - Total 770 769 100% 0.0 9 A 2360 2355 100% 0.1 18 B Left 10 10 100% 0.0 51 D Through 5 5 100% 0.0 41 D Right 5 5 100% 0.0 7 A U-Turn - - Total 20 20 100% 0.0 37 D Left 40 40 100% 0.0 45 D Through 20 20 100% 0.0 33 C Right 30 29 97% 0.2 10 A U-Turn - - Total 90 89 99% 0.1 31 C Left 40 37 93% 0.5 42 D Through 1170 1178 101% 0.2 12 B Right 40 39 98% 0.2 8 A U-Turn - - Total 1250 1254 100% 0.1 13 B Left 20 19 95% 0.2 41 D Through 730 729 100% 0.0 13 B Right 20 20 100% 0.0 10 A U-Turn - - Total 770 768 100% 0.1 13 B 2130 2131 100% 0.0 14 B TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB EB WB DKS Associates 8/18/2025Page 339 of 349 City of SLO - US101 Prado Road Interchange Alternative 2B AM 8 $ 9 70 (140)=<20 (105) 395 (865)"!155 (350) ?> : # ; 130 (250)135 (330) 25 (70) 30 (90) 8 $ 9 30 (80)=< 235 (585)"!150 (310) ?>20 (50) : # ; 10 (45) 5 (25) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 340 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 2B PM PEAK HOUR Page 341 of 349 City of SLO - US101 Prado Road Interchange Alternative 2B PM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 180 176 98% 0.3 37 D Through - - Right 150 152 101% 0.2 10 A U-Turn - - Total 330 328 99% 0.1 24 C Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 96 96% 0.4 35 D Through 600 604 101% 0.2 7 A Right - - U-Turn - - Total 700 700 100% 0.0 11 B Left - - Through 910 903 99% 0.2 16 B Right 780 785 101% 0.2 6 A U-Turn - - Total 1690 1688 100% 0.0 11 B 2720 2716 100% 0.1 13 B Left 30 28 93% 0.4 54 D Through 20 22 110% 0.4 42 D Right 20 20 100% 0.0 10 A U-Turn - - Total 70 70 100% 0.0 38 D Left 50 52 104% 0.3 50 D Through 10 11 110% 0.3 42 D Right 60 58 97% 0.3 15 B U-Turn - - Total 120 121 101% 0.1 32 C Left 50 50 100% 0.0 57 E Through 690 696 101% 0.2 9 A Right 10 8 80% 0.7 4 A U-Turn - - Total 750 754 101% 0.1 13 B Left 10 8 80% 0.7 58 E Through 1600 1594 100% 0.2 28 C Right 20 19 95% 0.2 24 C U-Turn - - Total 1630 1621 99% 0.2 28 C 2570 2566 100% 0.1 24 C EB WB TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB DKS Associates 8/18/2025Page 342 of 349 City of SLO - US101 Prado Road Interchange Alternative 2B PM 8 $ 9 60 (135)=<120 (645) 130 (325)"!390 (720) ?> : # ; 105 (200)40 (105) 30 (85) 45 (100) 8 $ 9 40 (105)=< 100 (200)"!525 (940) ?>10 (45) : # ; 25 (65) 20 (70) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/18/2025Page 343 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 3 AM PEAK HOUR Page 344 of 349 City of SLO - US101 Prado Road Interchange Alternative 3 AM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 240 235 98% 0.3 76 F Through - - Right 300 304 101% 0.2 118 F U-Turn - - Total 540 539 100% 0.0 100 F Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 98 98% 0.2 5 A Through 950 948 100% 0.1 5 A Right - - U-Turn - - Total 1050 1046 100% 0.1 5 A Left - - Through 420 417 99% 0.1 5 A Right 350 352 101% 0.1 1 A U-Turn - - Total 770 769 100% 0.0 3 A 2360 2354 100% 0.1 26 D Left 10 10 100% 0.0 13 B Through 5 5 100% 0.0 10 B Right 5 5 100% 0.0 3 A U-Turn - - Total 20 20 100% 0.0 10 A Left 40 40 100% 0.0 4 A Through 20 21 105% 0.2 4 A Right 30 28 93% 0.4 1 A U-Turn - - Total 90 89 99% 0.1 3 A Left 40 36 90% 0.6 7 A Through 1170 1178 101% 0.2 7 A Right 40 39 98% 0.2 2 A U-Turn - - Total 1250 1253 100% 0.1 7 A Left 20 19 95% 0.2 2 A Through 730 729 100% 0.0 1 A Right 20 21 105% 0.2 1 A U-Turn - - Total 770 769 100% 0.0 1 A 2130 2131 100% 0.0 5 A TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB EB WB DKS Associates 8/22/2025Page 345 of 349 City of SLO - US101 Prado Road Interchange Alternative 3 AM 8 $ 9 =<0 (0) 0 (0) "!55 (175) ?> : # ; 235 (910) 555 (1365) 25 (90) 8 $ 9 =< 70 (130)"!35 (115) ?> : # ; 15 (50) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/22/2025Page 346 of 349 US 101 AND PRADO ROAD INTERCHANGE • SENSITIVITY ANALYSIS • OCTOBER 2025 ALTERNATIVE 3 PM PEAK HOUR Page 347 of 349 City of SLO - US101 Prado Road Interchange Alternative 3 PM Intersection Approach Movement Demand Volume Served Volume % Served GEH Average Delay (s) LOS Left 180 177 98% 0.2 6 A Through - - Right 150 152 101% 0.2 6 A U-Turn - - Total 330 329 100% 0.1 6 A Left - - Through - - Right - - U-Turn - - Total - - 0 Left 100 95 95% 0.5 2 A Through 600 604 101% 0.2 2 A Right - - U-Turn - - Total 700 699 100% 0.0 2 A Left - - Through 910 901 99% 0.3 16 C Right 780 782 100% 0.1 3 A U-Turn - - Total 1690 1683 100% 0.2 10 B 2720 2711 100% 0.2 8 A Left 30 29 97% 0.2 6 A Through 20 21 105% 0.2 5 A Right 20 20 100% 0.0 2 A U-Turn - - Total 70 70 100% 0.0 4 A Left 50 52 104% 0.3 18 C Through 10 11 110% 0.3 19 C Right 60 57 95% 0.4 10 B U-Turn - - Total 120 120 100% 0.0 14 B Left 50 51 102% 0.1 5 A Through 690 698 101% 0.3 4 A Right 10 8 80% 0.7 1 A U-Turn - - Total 750 757 101% 0.3 4 A Left 10 9 90% 0.3 7 A Through 1600 1597 100% 0.1 6 A Right 20 19 95% 0.2 4 A U-Turn - - Total 1630 1625 100% 0.1 6 A 2570 2572 100% 0.0 6 A EB WB TABLE: AVERAGE DELAY Total Total Elks Ln / Prado Rd NB SB EB WB US 101 Ramps / Prado Rd NB SB DKS Associates 8/22/2025Page 348 of 349 City of SLO - US101 Prado Road Interchange Alternative 3 PM 8 $ 9 =<10 (80) 0 (0)"!295 (740) ?> : # ; 45 (125) 45 (120) 50 (135) 8 $ 9 =< 50 (105)"!160 (550) ?> : # ; 20 (75) TABLE: QUEUE COUNTERS (Avg/95th) 1: US 101 Ramps / Prado Rd 2: Elks Ln / Prado Rd DKS Associates 8/22/2025Page 349 of 349 Prado Road Interchange Value Analysis November 4, 2025 Bike Lane Classifications 2 Existing Condition 3 Project Overview 4 Related Corridor Projects Prado Interchange Prado Bridge Prado Extension Results Multimodal Corridor Address key growth areas such as San Luis Ranch, Margarita, Tank Farm) Implements projects contemplated by other environmental documents Improves congestion, safety, and emergency response 5 Bridge Project 4 – Travel Lanes 2 – Turn Lane 2 – Sidewalk 2 – Directional Protected Bike Lane 2 – On Street Bike Lanes 6 Bridge Project 7 Caltrans Delivery Process / Project Timeline Phase 1 - Project Study Report – Project Development Support - Completed in 2018 Phase 2 - Project Approval Environmental Document Preferred Alternative Selected (2023) Completed in 2024 Phase 3 – Plans, Specifications and Estimates Awarded to Consor Engineering (Feb 2025) Value Analysis Phase underway (2025) Caltrans Supplemental Project Report (2026) Phase 4 - Construction anticipated (2029–2031) 8 Value Analysis – Identified in 2023 Use Cast In Drilled Hole for column/shafts Use long-span precast girders Reduce design speed from 45 → 35 mph Narrow lanes & shoulders Increase recycled material use Estimated Savings: $8M 9 Value Analysis Lane Reductions Bridge Width Reduction: 103 ft → 63 ft Consolidated shared-use path on south side Segmented design tailored to context (3 segments) Design not complete – need high level input Estimated Savings: $12M 10 N Preferred Alternative Roadway Segment - Typical 4 – Travel Lanes 1 – Turn Lane 2 – On Street Bike Lanes 2 – Protected Directional Bike Lanes 2 - Sidewalks 11 Segment 1 2 – Travel Lanes 1 – Turn Lane 12 1 – Sidewalk 1 – Shared Use Path 2 – On Street Bike Lanes Segment 2 4 – Travel Lanes 1 – Turn Lane 13 1 – Sidewalk 1 – Shared Use Path 2 – On Street Bike Lanes Segment 3 4 – Travel Lanes 1 – Turn Lane 1 – Sidewalk 1 – Shared Use Path 2 – On Street Bike Lanes VS. 1 – Directional Protected Bike Lane 14 15Prado Corridor 162 Lane Signalized AM Peak Hour - Simulation N 172 Lane Signalized PM Peak Hour - Simulation N 1824-hour Demand/Capacity 192-Lane Overcrossing Operations •2050 Traffic Volumes Represent General Plan Full Build-Out •US101 On/Off Ramps Operate Acceptably •Prado Road Would Operate Acceptably up to 2045. •Beyond 2045 WB Prado Road in PM Peak Period Would Experience Spill Back Queuing to the Elks and Higuera Intersections Cost Comparison - Funding Strategy 20 1.Reduce Project Cost by VA 2.Obtain Grants •Project Grant Writer •City Wide Grant Consultant •SLOCOG •Lobbyist 3.Debt Financing Concurrences 21 Public Safety •Supports the Project noting the improved east–west connectivity •Improvements will reduce response times and increase safety •Noted the need for emergency-vehicle signal preemption throughout the project area. ATC •ATC supports an elevated shared use path on south side of Prado through entire length of project. •ATC supports a one-way bike lane on each side of the roadway throughout the entire length of the project. •ATC supports the use of Class 4 bike lanes throughout the project. •ATC supports the value analysis alternative with the added additions of the previous motions. ATC 22 ATC 23 Next Steps 24 25Recommendations 1.Receive an update on the Prado Road Interchange Project Value Analysis phase; and, 2.Direct staff to implement the Prado Road Interchange Project Value Analysis project changes that will reduce construction costs by approximately $8,000,000; and 3.Direct staff to implement the Prado Road Interchange Project travel lane reduction cost components that will reduce construction costs by approximately $12,000,000; and 4.Direct staff to implement a shared use path along the south side of Prado Road through the Prado Road Interchange Project and to Higuera Street. + Alternative 3 - Conduct a Value Analysis for the Bridge Project. Council could direct staff to complete a value analysis for the Bridge Project to identify potential opportunities for cost reduction. Staff anticipate this effort could be completed relatively quickly but may cost up to $100,000.