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HomeMy WebLinkAbout5/6/2025 Item 7c, Horn and Schwartz - Staff Agenda CorrespondenceCity of San Luis Obispo, Council Memorandum Council Agenda Correspondence DATE: May 6, 2025 TO: Mayor and Council FROM: Matt Horn, Public Works Director PREPARED BY: Luke Schwartz, Transportation Manager VIA: Whitney McDonald, City Manager SUBJECT: ITEM 7C - 7.c DISCUSS AND PROVIDE DIRECTION ON TANK FARM ROAD STRIPING MODIFICATIONS AND AUTHORIZE ADVERTISEMENT OF THE 2025 PAVING PROJECT (SPEC. NO. 2000616) FOR CONSTRUCTION Staff received the following questions regarding the 2025 Paving Project and Tank Farm Road Striping Modifications. The questions are listed below in bold with staff’s responses shown in italics: 1) Why is no left turn pocket proposed for the Tank Farm driveway entry into the Marigold Center? If the choice is Tank Farm Alternate #1 (Road Diet), could the road be restriped in the future to revert to Alternate #2 (No Road Diet)? Both of the current design concepts for Tank Farm Road retains the existing left turn lane into the Marigold Center driveways – both the primary customer access driveway and the delivery driveway just east of the primary driveway. Tank Farm Alternative 1 (Road Diet) is currently designed so that conversion back to the existing five-lane road configuration could be done in the future. This would require removal of existing pavement markings, resealing of the roadway, and installation of new striping—costly roadway excavations would not be required. 2) Please address an ATC member’s concern about high vehicle speeds through the roundabout at Tank Farm & Righetti Ranch Road. The current project designs include several measures to encourage slower speeds entering the roundabout at Tank Farm/Righetti Ranch, including radar speed feedback signs, roundabout warning signs with 15 mph advisory speed plaques and flashing yellow warning beacons on the eastbound/westbound approaches to the roundabout. The proposed road diet west of Righetti Ranch in Alternative 1 and striping modifications east of Righetti Ranch, which narrow the traffic lane widths, are also intended to reduce vehicle speeds. Item 7c – 2025 Paving Project and Tank Farm Road Striping Modifications Page 2 Transportation staff explored additional strategies using striping modifications and pavement markers (bots dots) within the roundabout itself to provide further channelization and deflection for vehicles traveling through the roundabout to reduce speeds further. Following staff’s review of these strategies with the City’s engineering design consultant for the striping on Tank Farm Road, it is expected that these measures would have limited effectiveness, and, as a result, they are not shown in detail in the current concept plans. With that said, staff could revisit these strategies again in guiding the final designs for Tank Farm Road and will continue to monitor speeds and driver behavior following the 2025 Paving Project to determine if future speed reduction measures are warranted. 3) Flex posts seem to be identified as optional, so is staff looking for Council direction on whether or not to include them? Does Tank Farm Alternative 1 allow for future potential of barrier-protected bike lanes? The Tank Farm Alternative 1 design does provide the physical space that would be needed to add future on-street protected bike lane barriers. However, the staff recommendation is not to add protected bike lane vertical elements, such as flex posts, at this time based on concerns that this could potentially narrow the roadway width and impede emergency response and evacuation efficiency during a large-scale emergency event. Furthermore, bike lane barriers are not included in the estimated cost of the project and additional funding would likely need to be identified upon award of the project. For example, flex post barriers would add an estimate of $50,000 to $75,000 to the project Base Bid cost. Currently, the estimated cost of the project’s Base Bid, plus soft costs, is equivalent to the available funding identified. Protected bike lanes may still be feasible in the future; however, alternative design strategies would likely need to be explored that do not require physically narrowing the width of the roadway. For example, an elevated sidewalk-level protected bike lane or shared-use bicycle/pedestrian path could potentially constructed, but it would require removal of the landscaped parkway including street trees, and/or widening the sidewalk area along each side of Tank Farm Road without narrowing the curb-to-curb width. This concept would require further investigation to confirm feasibility and potential costs, and there is currently no budget for this concept included in the FY25/27 Financial Plan. 4) Why was Tank Farm built as a four-lane road on this section? Was there anticipated growth beyond what is currently shown in the land use map? It does appear that previous long-term traffic projections indicated a higher future volume on Tank Farm Road than current projections based on updated forecasts of build-out per the City’s adopted General Plan. For example, studies prepared for the Orcutt Area Specific Plan (2007), projected future build-out volumes of approximately 27,000 average daily vehicle trips along Tank Farm Road between Broad Street and the UPRR Rail Bridge, where current projections for future build-out conditions project volumes of less than 20,000 vehicles per day on this road segment. Item 7c – 2025 Paving Project and Tank Farm Road Striping Modifications Page 3 One potential reason for this change is that many of the large-scale subdivisions that have been approved in recent years (i.e. San Luis Ranch, Avila Ranch, Froom Ranch Specific Plan, Airport Area Specific Plan) have seen final development plans that are less traffic-intensive than the land uses previous anticipated for these sites, with a higher concentration of residential and mixed-use development reflected in final land use plans, where larger commercial uses (i.e. big box retail, business park, etc.) were originally anticipated. 5) Several members of the public noted concerns about eastbound left-turns on Tank Farm into the Marigold Shopping Center. Please comment on the issue. Can a “KEEP CLEAR” zone be established? There are peak times of day when the westbound left-turn lane queues at the Broad/Tank Farm signalized intersection spill back towards the Marigold Shopping Center driveway within the center turn lane, which can impede the ability of eastbound vehicles attempting to enter the left-turn lane to enter the Marigold Center. During these instances, eastbound vehicles waiting to turn left into the Marigold Center Driveway can sometimes queue within the inside eastbound through traffic lane, requiring eastbound through traffic to merge into the second eastbound lane to bypass these queued vehicles. Some residents have commented that the proposed lane reductions included in Tank Farm Alternative 1 (Road Diet) would impede the ability for eastbound through traffic to continue to bypass queues during these periods. Transportation staff is currently working on refinements to traffic signal timings at the Broad Street/Tank Farm intersection to reduce the westbound left turn queues from spilling back to the Marigold Center Driveway. These timing refinements will be implemented ahead of the 2025 Paving project, regardless of which design alternative is advanced for Tank Farm Road. As an additional precautionary measure, the proposed striping designs for the road diet alternative preserve sufficient clear width for eastbound vehicles going straight to continue to go around a queued vehicle when attempting to enter the turn lane for the Marigold Center Driveway. Item 7c – 2025 Paving Project and Tank Farm Road Striping Modifications Page 4 The following alternative measures were evaluated to address this concern, but ultimately not recommended by staff as part of Alternative 1 (Road Diet): a) Retain 2 Eastbound Lanes on Tank Farm East of Poinsettia: This option would retain two eastbound traffic lanes, as currently exist, east beyond the Marigold Center and Poinsettia intersection before merging down to a single eastbound lane. This option would preserve two eastbound traffic lanes through the Marigold Center Driveway but was not recommended in the current striping plans in order to prioritize pedestrian safety at the Tank Farm/Poinsettia intersection crossing – preserving two traffic lanes through the pedestrian crossing would likely decrease the rates of drivers yielding to pedestrians and may increase the risk or multiple threat collisions1. b) Retain 2 Eastbound Lanes on Tank Farm, with the Outside Lane Becoming a Right-Turn Only “Trap Lane” at Poinsettia: This option would retain two eastbound traffic lanes past the Marigold Center Driveways, with the outside traffic lane becoming a right-turn only “trap” lane at Poinsettia. This option would preserve two lanes though the Marigold Center Driveways, but was not recommended in the current striping plans for the following reasons: o Trap right-turn only lanes can be problematic when the vast majority of drivers intend to continue traveling straight through an intersection. This is because some drivers mistakenly realize they are in the right-turn only lane too late and make unsafe lane changes approaching the intersection to continue straight. Similarly, some drivers tend to continue straight from the right-turn only lane illegally in order to pass others. The current percentage of eastbound vehicles turning right at the Tank Farm/Poinsettia intersection is small (10%), with more than 85% continuing straight. Staff believes a right-turn only trap lane would likely result in undesirable driver behaviors. o Where right-turn only lanes are provided on streets with striped bike lanes, state/federal design standards require that the bike lane either (a) merge to the left of the right-turn only lane, or (b) end ahead of the intersection, requiring cyclists to merge into and share the vehicle traffic lane. Either option is uncomfortable for many cyclists and not recommended with this project. 1 Multiple-threat collisions describe the scenario that can occur where an uncontrolled pedestrian crossing exists on streets with multiple traffic lanes in each direction. In these contexts, there is potential for the driver in one lane to stop to yield to a pedestrian in the crosswalk, impeding the visibility for drivers in the second traffic lane, who may continue through the intersection without stopping, increasing potential for vehicle vs. pedestrian collisions. Item 7c – 2025 Paving Project and Tank Farm Road Striping Modifications Page 5 6) Please confirm if existing bike lanes on Sacramento are wider on one side of the street than the other, and if so, is it possible to make these widths the same and is there room for buffers? Yes, currently, the bike lane on the west side (southbound direction) of Sacramento is generally wider than the bike lane on the east side (northbound direction) of the street. The total width of Sacramento Drive varies--the draft striping plans include the following typical cross section widths: 1) Basil Street south around roadway curve: While not part of the paving area, striping changes to this segment include 6’ bike lane, 1.5’ buffer, 10.5’ travel lane 2) Via Esteban to Capitolio: 6’ bike lanes, 10’ travel lanes. There is no width for bike buffers. 3) Capitolio to 3621 Sacramento: 6’ bike lanes, 10’ travel lanes, 8.5’-9’ parking on the west side only. There is no width for bike buffers. 4) 3621 Sacramento to Industrial Way: 5’ bike lane, 2’ buffer, 10’ travel lane, 10’ parking on west side only. As noted above, the current plans propose to provide equal bike lane widths on the east and west sides of the street and add striped buffers where street width allows. Note that staff considered narrowing the on-street parking lane on the west side of Sacramento to increase the available width for the bike lanes, but ultimately opted against this due to the frequency of large trucks using this parking lane and potentially encroaching into the adjacent bike lane. 7) Can you please compare traffic volumes on Tank Farm Road vs. other streets that have had road diets implemented recently? The following table compares current vehicle traffic volumes on Tank Farm Road to other streets in San Luis Obispo where road diets (4/5-lane to 3-lane conversion) have been implemented. Street Segment Average Daily Traffic (ADT) Average Daily Traffic (ADT) by Direction Tank Farm Rd Broad to UPRR 10,979 EB 5,442; WB 5,537 UPRR to Orcutt 5,578 EB 2,855; WB 2,723 Johnson Ave Sydney to Laurel 11,446 NB 5,496; SB 5,950 Laurel Ln Southwood to Orcutt 11,116 NB 5,362; SB 5,754 South St Higuera to Broad 17,508 EB 8,948; WB 8560 Item 7c – 2025 Paving Project and Tank Farm Road Striping Modifications Page 6 8) Can you please provide more information on why the crosswalk at the Tank Farm/Poinsettia intersection is proposed to be relocated from the west side of the intersection to the east side? There are several reasons behind the recommendation to shift the crosswalk to the east side of the Tank Farm/Poinsettia intersection: 1. There are significantly more northbound left-turns from the south leg of Poinsettia to Tank Farm than southbound left-turns from the north leg of Poinsettia to Tank Farm (10x more). Shifting the crosswalk to the east leg reduces conflicts between left-turning vehicles and pedestrians in the crosswalk. There was a severe injury collision involving a pedestrian in 2014 at this intersection due to a driver making the northbound left turn and failing to yield to a person in the crosswalk. 2. There is existing streetlighting at the southeast corner of the intersection, but none on the west side where the existing crosswalk is located. The current design proposal is to shift the crosswalk to the east leg and add a second streetlight at the northeast corner so that the full crosswalk width is well illuminated. 3. Shifting the crosswalk to the east leg of the intersection provides more distance for eastbound drivers to see the crossing conflict and yield to a pedestrian crossing the street. It is staff’s opinion that this adds value under the road diet alternative, as it allows drivers to first focus on the merge from 2 to 1 eastbound lanes, then focus their attention to the intersection conflicts ahead. 4. With the crossing on the east side, there is greater potential to reserve space for a median refuge than with the crossing on the west side. Staff understands that this recommendation may add additional distance/exposure crossing Poinsettia Street if a pedestrian happens to be starting from the west side of the intersection. If they are approaching from the east side of Poinsettia (i.e. walking to Tank Farm from French Park), the proposed crossing on the east side may be more convenient or essentially the same as the current crosswalk location on the west side. Ultimately, staff’s intent was to maximize visibility for pedestrians crossing Tank Farm itself and to try to reduce conflicts with left-turning vehicles turning from Poinsettia to Tank Farm, where previous collisions with pedestrians have occurred. With all that said, staff can revise the design to retain the crosswalk on the west side of the intersection if that aligns with what the community and Council prefer.