HomeMy WebLinkAbout2/17/2026 Item 6b, Floyd and Schwartz - Staff Agenda CorrespondenceCity of San Luis Obispo, Council Memorandum
City of San Luis Obispo
Council Agenda Correspondence
DATE: February 17, 2026
TO: Mayor and Council
FROM: Aaron Floyd, Public Works and Utilities Director
Prepared By: Luke Schwartz, Transportation Manager
VIA: Whitney McDonald, City Manager
SUBJECT: ITEM #6b - REQUEST TO ADVERTISE THE HIGUERA COMPLETE
STREETS AND REVISED 50 HIGUERA WIDENING PROJECTS FOR
CONSTRUCTION
Staff received the following questions, regarding the Higuera Complete Streets Project.
The questions are below in bold with staff’s response shown in italics:
1) The Higuera Complete Streets Project evacuation study shows modeling
using the LADRIS tool. The various models show “addresses evacuated”
and “passenger cars.” The explanatory text states that 2 cars are evacuating
per household as a base assumption. Can you explain how these numbers
are calculated? It seems that “passenger cars” should be two times
“addresses evacuated.”
The SLO Fire Safe Council, who prepared the evacuation analysis, uses the
LADRIS evacuation model to estimate evacuation demand for both residential and
nonresidential properties within the selected zones.
The model relies on County land use data and City zoning classifications to assign
estimated population and traffic demand to each parcel. For residential properties,
the base assumption is generally two vehicles per household.
However, “addresses evacuated” does not directly translate to “passenger cars” at
a one-to-two ratio because many properties, particularly multifamily and
nonresidential uses, may have a single address but contain multiple households
or large occupant populations. In these cases, the model estimates maximum
occupancy using local land use data and zoning data, then applies a two-persons-
per-vehicle factor to project anticipated vehicle counts.
Additional verification is conducted using site-specific methods when appropriate.
For example, the analysis may:
• Count the number of trailers in a mobile home park that has a single
address,
• Review the number of beds and staff at a hospital or care facility, or
Item 6b Staff Agenda Correspondence Page 2
• Evaluate parking spaces at commercial centers or schools to estimate
potential vehicle demand.
This methodology allows the model to account for single family homes, multifamily
developments, mobile home parks, and nonresidential uses in a comprehensive
and defensible manner.
2) The Zone 25 analysis in the evacuation study shows two different “response
times.” What is response time and how is it determined?
In the LADRIS evacuation model used for this analysis, “response time” refers to
the estimated time between when an evacuation is issued and when evacuees
enter the roadway network. In other words, it reflects the time residents take to
receive the order, prepare to leave, and begin driving.
Response time is an assumed input based on professional judgment and the
context of the emergency scenario being analyzed. For suburban wildfire
evacuations, a typical modeled response time generally ranges from 30 to 90
minutes, depending on the location and nature of the event.
A longer response time does not necessarily mean a longer overall evacuation.
While it increases the time before vehicles enter the roadway network, it may also
distribute departures over a longer period, reducing peak congestion and
improving travel speeds. Conversely, a shorter response time can concentrate
vehicle departures, which may increase congestion and slow roadway travel, even
though residents begin evacuating sooner.
In the evacuation study attached with the Council Agenda Report (dated 1/18/26),
the Zone 25 fire scenario inadvertently used a response time of 1 hour and 17
minutes for the “with Complete Streets Project” scenario, while a 1-hour response
time was used consistently in the other modeled scenarios.
The Zone 25 “with Complete Streets Project” scenario has since been re -run using
a 1-hour response time to ensure consistency across all scenarios. The updated
analysis results in a total evacuation clearance time of 1 hour and 42 minutes, one
second shorter than the previously reported result.
In this case, the overall evacuation clearance time remained substantially
unchanged because the reduction in assumed response time (residents beginning
to evacuate sooner) was offset by a corresponding increase in roadway congestion
due to more concentrated vehicle departures.
An updated copy of the Evacuation Study is attached to this Agenda
Correspondence for reference. The overall findings and conclusions of the analysis
remain substantially consistent with the previously provided version.
Item 6b Staff Agenda Correspondence Page 3
3) Can further design measures be considered at the intersection of Higuera
and Marsh Street to address the following concerns?
A. Bicyclists traveling southbound on Higuera approaching Marsh Street
have to merge across vehicles entering the right-turn lane heading
towards the US 101 ramps, which can be uncomfortable.
B. Eastbound drivers exiting the US 101 ramps and turning right to
southbound Higuera frequently do not stop or yield to southbound
bicyclists.
Yes, additional design measures could be considered at the Higuera/Marsh
intersection to address the concerns identified. The following provides additional
context for each item.
Concern A: Other design strategies were considered to reduce the conflicts
between southbound cyclists and right-turning vehicles heading towards the US
101 ramps at Marsh Street. The ideal solution would be to realign the bike lane to
remain along the curbside and separate the conflict with right-turning vehicles
through a dedicated bicycle signal phase. Under this approach, bicyclists would
receive a green signal while right-turning vehicles would receive a red indication
during the bicycle phase.
This type of treatment is being implemented at the Higuera/Madonna and
Higuera/Los Osos Valley Road intersections as part of the current project.
However, when this strategy was evaluated for Higuera/Marsh, there were
concerns regarding impacts to traffic operations, particularly increased queueing
that could extend onto the US 101 off-ramp, as well as associated with signal
reconstruction and upgrades. For those reasons, it was not included in the current
project scope.
If there is interest from the Council and community in exploring these strategies,
staff would recommend this be considered in a future budget request. This could
potentially be incorporated into a broader effort to improve pedestrian and bicycle
connectivity between the Higuera/Marsh intersection and the shared-use path near
the Madonna Inn, which currently terminates near the Cerro San Luis trailhead
parking lot.
Concern B: Eastbound drivers exiting the US 101 ramps and turning right onto
southbound Higuera have been observed failing to adequately yield to bicyclists.
The Higuera Complete Streets Project includes high -visibility green pavement
markings through the conflict area to increase awareness of the bicycle crossing
and improve yielding behavior (see plan excerpt below for reference).
Item 6b Staff Agenda Correspondence Page 4
Additional measures that could be explored in a future project include removing
the existing channelized right-turn configuration and/or converting the right-turn
movement from yield control to signal control. Under a signalized configuration,
drivers would be legally required to stop on red before proceeding. A similar
conversion was recently completed at the westbound approach to the
Higuera/Tank Farm intersection, which required traffic signal reconstruction.
These additional treatments would require further traffic analysis, design, and
funding but could be evaluated if directed by Council.
Excerpt from Higuera Complete Street Plans Showing Green Markings Added to
Right Turn Conflict Area
4) Please confirm the intended path for southbound cyclists to navigate the
Higuera & Madonna intersection with the proposed project and how conflicts
between cyclists and right-turning vehicles are addressed.
The plans include reconfiguration of the northwest corner of the Higuera/Madonna
intersection and modifications to the traffic signal to eliminate the need for
southbound cyclists to weave across multiple traffic lanes to continue southbound.
With the proposed improvements in place, southbound cyclists will remain on the
right side of the roadway as they approach and enter the intersection. Cyclists will
proceed through the intersection using a new dedicated bicycle signal phase .
During this phase, right-turning vehicular traffic will receive a red light and will be
subject to NO RIGHT ON RED restrictions.
See plan excerpt and example traffic signal phasing graphic below for reference.
Item 6b Staff Agenda Correspondence Page 5
5) Please confirm how the project improves conditions for cyclists on
northbound Higuera Street to navigate the segment between Madonna Road
and South Street, and confirm if there are further design measures that can
be explored to reduce conflicts between cyclists and vehicles exiting the gas
station on the east side of Higuera Street at this intersection?
Improving conditions for northbound cyclists between Madonna Road and South
Street was one of the most significant design challenges in this project.
Currently, there is insufficient width along this segment to maintain a dedicated
northbound bike lane. As a result, the existing bike lane ends, and cyclists are
required to share the traffic lane, including crossing the right-turn lane in order to
continue northbound past South Street.
Item 6b Staff Agenda Correspondence Page 6
Staff evaluated options to widen the roadway to accommodate a continuous
northbound bike lane; however, this would require roadway widening and could
impact the adjacent building frontage. Due to those constraints, widening was
determined to be infeasible as part of this project.
A dedicated bicycle signal phase was also considered. However, bicycle signal
phases require a dedicated bicycle lane and cannot be implemented where cyclists
are sharing a general-purpose travel lane with vehicles. Because a continuous
northbound bike lane cannot be accommodated through this segment, a bicycle-
only signal phase is not operationally appropriate at this location.
Given these constraints, the project includes the following improvements:
• Installation of green-colored shared lane markings to increase the visibility
and awareness of cyclists operating within the travel lane; and
• Improvements to the low-stress, parallel neighborhood greenway route east
of Higuera Street via Bridge Street, which provides an alternate northbound
route toward downtown for cyclists who prefer to avoid this higher-stress
segment of Higuera Street.
Regarding potential conflicts with vehicles exiting the gas station on the east side
of Higuera Street, staff can explore additional bicycle warning signage or pavement
markings to further alert exiting drivers to the presence of cyclists. More substantial
geometric modifications would require additional study, design, and funding and
could be considered as part of a future project if directed by Council.
6) Please confirm the intended path for southbound cyclists to navigate the
Higuera & Los Osos Valley Road intersection with the proposed project and
how conflicts between cyclists and right-turning vehicles are addressed. Are
there design measures that can be explored to improve options for cyclists
traveling northbound on Higuera to make a left turn to westbound Los Osos
Valley Road?
For southbound cyclists, the design approach at the Higuera/Los Osos Valley
Road intersection is consistent with the treatment proposed at Higuera/Madonna.
Under the proposed project, the southbound bicycle lane is realigned to remain
along the curbside rather than requiring cyclists to weave across right -turning
vehicle traffic. A new dedicated bicycle signal phase will allow southbound cyclists
to proceed through the intersection while right-turning vehicles receive a red
indication. This signal separation reduces vehicle–bicycle conflicts and eliminates
the previous merge condition.
Item 6b Staff Agenda Correspondence Page 7
Regarding northbound cyclists seeking to turn left onto westbound Los Osos Valley
Road, the current design maintains standard vehicular left-turn operations. Cyclists
traveling northbound may merge into the left-turn lane and complete the turn as a
vehicle would, or they may use a two-stage turn maneuver (crossing first and then
repositioning to complete the turn during a subsequent signal phase).
.
If Council is interested in further enhancing this movement, staff could evaluate the
addition of a bicycle two-stage left-turn box (also known as a bike turn box) on the
northbound approach. This treatment—similar to what is proposed on the
eastbound Los Osos Valley Road approach—would provide a designated waiting
area within the intersection to facilitate a more comfortable two-stage left-turn
maneuver for cyclists.
Implementation of this measure would require additional traffic signal evaluation
and striping design but could be explored as a refinement if directed by Council.
7) How much would it cost for “feasibility studies, environmental review and
formal design work” to take the Madonna Shared-Use Path along the
Madonna Road Overpass to the next stage?
Based on recent feasibility discussions with Caltrans following publication of the
Council Agenda Report, it appears likely that advancing the Madonna Shared -Use
Path across the Madonna Road overpass will require widening the existing
Madonna Road bridge over US 101 or constructing a separate parallel
pedestrian/bicycle bridge in order to safely extend the facility.
Item 6b Staff Agenda Correspondence Page 8
Based on comparable highway bridge projects of similar scale and complexity,
staff estimates that preparation of a Project Initiation Document (PID)—including
scoping, alternatives analysis, conceptual engineering, structural review,
preliminary environmental review, and cost estimating—would likely cost
approximately $300,000 to $500,000.
Advancing a project of this magnitude through environmental clearance and formal
design to a shovel-ready phase could require total pre-construction funding in the
range of $3 million to $5 million, depending on the selected alternative and
associated environmental and structural requirements.
If Council is supportive of prioritizing advancement of this project prior to
development of the FY 2027–29 Financial Plan, Public Works staff would need to
evaluate current staffing capacity and funding availability. In addition, advancing
this effort would likely require Council direction to defer or reprioritize other active
projects or programs in order to accommodate the necessary resources.
8) Does the proposed work on Higuera street address removing the dirt/gravel
parking lot driveway intruding into the bike path, located just north of the
Chumash Village access? Did the City acquire the rights to remove this
property? What is the plan for future right-of-way acquisition, and are there
any options for protecting northbound bicyclists where they encounter the
lane narrowing due to the narrower street width?
Efforts to construct permanent roadway widening, curb, gutter, and sidewalk
improvements along the east side of Higuera Street between Margarita Avenue
and Fontana Avenue have been underway for several years under a separate
Capital Improvement Program (CIP) project.
Construction of those improvements, including removal of the dirt/gravel parking
lot driveway area encroaching toward the bike lane , requires acquisition of
additional off-site right-of-way. To date, attempts to secure the necessary right-of-
way have not been successful. The City has not acquired the property rights
needed to fully remove and reconstruct that frontage.
Earlier conceptual designs for the Higuera Complete Streets Project assumed that
these widening improvements could be delivered in advance of, or concurrently
with, the Complete Streets work. Due to right-of-way constraints, that assumption
proved infeasible.
The current Complete Streets Project therefore includes partial roadway widening
and temporary gutter/drainage improvements that can be constructed within the
existing public right-of-way. These improvements do not preclude future full
roadway widening if right-of-way acquisition is ultimately successful.
Item 6b Staff Agenda Correspondence Page 9
Regarding protection for northbound bicyclists through the approximately 200-foot
constrained segment north of Chumash Drive: this stretch includes a bus stop and
multiple driveways without formalized curb cuts. Due to these access points and
the limited roadway width, installation of continuous vertical separation (such as
curb-protected bike lanes or delineator posts) is not feasible at this time.
To improve visibility and awareness within these constraints, the project includes
continuous dashed green pavement markings through the narrowed segment to
highlight the shared space and increase driver awareness of bicyclists. While no
physical separation is provided under the current design, additional protective
measures could be revisited in the future if right-of-way acquisition is achieved and
the corridor can be fully reconstructed.
See the attached plan excerpt for additional detail on the design treatment at this
pinch point.
9) With the additive concrete barriers, are our fire vehicles capable of clearing
them in case of emergency where the turning lane is unavailable?
The proposed concrete barriers are not intended to be mounted by emergency
vehicles or passenger vehicles. The barriers are approximately 6 inches in height
with rounded edges. While it may be physically possible for certain vehicles to
mount them in a dire emergency, the project design assumes that mounting the
barriers is not required for standard emergency response or evacuation
operations.
Item 6b Staff Agenda Correspondence Page 10
Project designs are reviewed with emergency service providers under the
assumption that emergency vehicles should be able to operate within the available
travel lanes and turning movements without the need to traverse vertical
separation elements.
Similarly, while flexible delineator posts could potentially be driven over in an
extreme situation, it is not desirable for emergency vehicles , or passenger
vehicles, to rely on mounting vertical elements for routine access.
There are examples of vertical bikeway separators that can be more easily
mounted by emergency vehicles or passenger vehicles, such as small rubber
“armadillos”, low-height rounded rubber or concrete curbs; however, there are also
trade-offs with these options:
• Any vertical element that can be easily mounted, will also be inherently less
effective at preventing undesired vehicle encroachment into the bike lanes
• If bikeway vertical features are designed to allow emergency vehicles to
mount and straggle them, then taller non-mountable vertical elements, such
as flex posts, need to be omitted or used very sparingly. This approach
limits the vertical visibility of these low-height barriers, which can increase
potential for accidently crashes into the vertical elements by vehicles and
cyclists. See examples of low-height (3”-4”) mountable bikeway curbs in
the City of Long Beach:
o Costa Del Sol Way Bikeway
o E Del Amo Boulevard Bikeway
It should also be noted that mountable low-height curb systems are typically
constructed as cast-in-place concrete (poured directly onto the roadway surface).
Unlike the proposed pre-cast concrete barriers included in the project Bid Additive
Alternative, cast-in-place curbs are not easily removable if future operational
adjustments are desired.
If Council prefers a more mountable separator design, staff can further evaluate
that option; however, it would involve balancing emergency flexibility, day -to-day
safety performance, visibility, and long-term adaptability.
10) Do the flex post barriers create just as much additional cost/challenge for
clearing the bike lanes, or is there a difference between how we clear the
lane with each barrier type?
In general, ongoing bike lane sweeping costs are expected to be similar whether
flex posts or concrete barriers are used—provided the bikeway width is insufficient
to accommodate the City’s standard mechanical street sweeper, which requires
approximately 11 feet of clear width.
Item 6b Staff Agenda Correspondence Page 11
Where the bikeway is narrower than that threshold, maintenance crews must use
smaller, more specialized equipment or manual methods to clear debris, and that
operational approach would be required regardless of barrier type.
There are, however, differences in durability and replacement costs. Flex posts
typically have lower upfront costs but are more susceptible to damage over time
and may require more frequent replacement. Concrete barriers are generally more
durable and less likely to require routine replacement, but they have higher initial
installation costs.
It is worth noting that the flex post mounting system proposed for this project is
designed to allow relatively straightforward replacement compared to some other
post systems, which can reduce labor time when repairs are needed.
11) Is the plan for the Walker Street closure completely in line with what is
presented in the Mid-Higuera Enhancement Plan? I wasn't sure if the plans
as presented here are a modification or a simplification of that vision. Is it
only Walker between Pacific and Pismo that will be impacted?
The proposed Walker Street closure is functionally consistent with the vision
outlined in the Mid-Higuera Enhancement Plan; however, the current project
represents a more modest, interim implementation rather than the full long -term
buildout envisioned in that plan.
The Mid-Higuera Enhancement Plan contemplates a more robust transformation
of Walker Street, including widening the roadway to create a formal cul-de-sac,
raising the street to sidewalk grade, and constructing a permanent pedestrian
plaza with landscaped planters, trees, and public art.
Advancing this long-term vision at this time would require:
• Significant additional capital funding,
• Acquisition of off-site private right-of-way to provide width for an emergency
vehicle turnaround, and
• Additional hydraulic analysis and drainage improvements—the existing
intersection is within the floodzone, so grading changes such as brining the
street up to a sidewalk level would require more significant analysis and
mitigation of flooding concerns.
The current project advances the functional and safety objective identified in the
Mid-Higuera Enhancement Plan, closing one leg of the irregular intersection
consistent with the Mid Higuera Enhancement Plan with more interim to improve
safety and simplify operations, while implementing more interim improvements that
can be constructed within the existing public right-of-way and available budget.
Item 6b Staff Agenda Correspondence Page 12
Importantly, the proposed design does not preclude future construction of the more
permanent pedestrian plaza envisioned in the Mid-Higuera Enhancement Plan,
should funding and right-of-way acquisition opportunities arise.
The closure only impacts Walker Street between Pacific Street and Pismo Street,
consistent with the configuration shown in the Enhancement Plan.
Excerpt from Mid Higuera Enhancement Plan
Item 6b Staff Agenda Correspondence Page 13
Excerpt from Higuera Complete Street Plans
12) Does the section of Higuera between Bridge and Margarita see the highest
bicycle traffic of this corridor?
Based on the latest traffic count data available, the average daily bicycle volumes
along Higuera Street between Marsh and Los Osos Valley Road range from apx.
200-350 bikes/day.
In general, bike volumes are slightly higher north of Madonna Road than south of
Madonna.
The segment between Bridge Street and Margarita had a volume of apx. 235
bikes/day, similar to other segments south of Madonna Road. Based on this data,
the Bridge–Margarita segment does not appear to carry the highest bicycle
volumes within this corridor.
13) I like all the language about monitoring and modifying the project based on
performance. It seems like that mostly applies to removing components. Are
we easily able to make pedestrian and bicycle infrastructure more robust in
areas if we continue to have safety issues in particular areas?
The ability to strengthen pedestrian and bicycle infrastructure depends on the type
of improvements desired. Low-cost measures—such as additional radar speed
feedback signs, extra green pavement markings, minor traffic signal adjustments,
additional flex posts, or warning signs—can generally be installed quickly and at
reasonable cost. More substantial measures—like adding concrete curbs, raising
bike lanes to sidewalk level, major signal modifications, significant lighting
upgrades, or intersection reconstruction—would require more time and funding. In
monitoring “after project” conditions, staff will also take in public feedback and
findings from crash data to guide future recommendations and areas for
improvement.
14) If concrete curb separators are not included in the project, could they be
added later? Are there additional costs associated with doing them later
versus with the current project?
Yes, concrete curb separators can be added later if the Council chooses not to
include them in the initial construction. There may be some additional cost due to
mobilization and potential construction escalation, but it is not expected to be
substantial.
It is important to note that some form of bikeway separation is required to meet the
project’s current grant funding requirements. Deferring all vertical elements (flex
posts and concrete curbs) could require relinquishing the grant, rescoping the
project under non-grant funds, or pursuing future grants to fund these elements.
Item 6b Staff Agenda Correspondence Page 14
15) Do the estimated evacuation times account for the "evacuation signal timing
plans" discussed on page 332?
No, the LADRIS software is a planning-level model and does not have the
capability to reflect detailed traffic signal operations in estimating evacuation
clearance times. The results provided in the evacuation study are assumed to be
conservative, in that they do not reflect the recommendation to pre-program
evacuation signal timing plans.
16) If the flex posts require more maintenance, how does the higher upfront cost
of concrete curbs compare to the long term increased maintenance cost of
the flex posts?
Based on a planning-level calculation, it is expected that over a 20-year timeframe,
using concrete curbs (between Bridge Street and Margarita only) would reduce the
maintenance costs associated with replacing flex posts by apx. $90,000-$120,000,
but would incur an additional upfront construction cost of $300,000 -$500,000.
17) Since the Elks Lane traffic signal is a required mitigation for the Prado Creek
Bridge Project, is the signal fully funded from that project's budget?
The current recommendation is to transfer $500,000 from the Prado Creek Bridge
Project to the Complete Streets Project, which is estimated to cover the costs
specific to this new traffic signal, excluding curb ramp upgrades, traffic control,
paving, sign and striping costs, which will likely exceed this $500,000 amount and
be covered from other project funding sources. If desired, the Council could direct
staff to transfer additional funds from the Prado Creek Bridge Project if actual bids
for the Higuera/Elks traffic signal come in higher than $500,000.
18) There are a few intersections along S. Higuera where bike boxes are being
added to easy left turns for those on bikes. However, I note these features
are not being proposed for the S. Higuera/Prado intersection or the
Margarita/S. Higuera intersection. (p 354/355) Would these be appropriate
additions for those two intersections? Why or why not?
Staff evaluated the feasibility of adding two-stage left-turn bike boxes at the noted
intersections.
• At Higuera/Margarita, a northbound two-stage turn box could potentially be
accommodated.
• At Higuera/Prado, and for the southbound direction at Higuera/Margarita,
there is insufficient roadway width to accommodate bike boxes without
impacting other critical elements.
It should also be noted that the Higuera/Prado intersection is planned to be
reconstructed as a protected intersection as part of the Prado Creek Bridge
Project. That future configuration is expected to significantly improve comfort and
safety for cyclists making left turns on all approaches.
Item 6b Staff Agenda Correspondence Page 15
19) Page 359 of the packet shows the intersections at Bridge Street and South
Higuera as well as Madonna/S. Higuera. Great changes are proposed for
Bridge/S. Higuera. And there are also changes proposed for southbound
bike/car traffic on South Higuera and for those turning right onto Madonna.
However, can you please clarify:
a) What intended path of travel would be for riders leaving the shopping
center driveway, continuing onto Madonna?
As shown in the image below, cyclists exiting the Pacific Coast Center and
desiring to continue westbound to Madonna Road would have two options:
1. Use the bike/pedestrian ramp at the northwest corner to access the
westbound bike lane; or
2. Continue in the vehicle lane briefly and merge into the street-level
westbound bike lane downstream.
Under the current and proposed signal phasing, no other vehicles are
permitted to turn onto westbound Madonna Road concurrently with
westbound cyclists. Therefore, under Option 2, cyclists would not encounter
conflicting turning vehicle traffic, other than vehicles also exiting the
shopping center driveway.
.
b) What safety enhancements are being proposed for bikes heading
northbound on S. Higuera leading up to the intersection at South/S.
Higuera where there is currently a “choke point” where I believe
several bike accidents have occurred?
See staff response to Question #3 above.
Item 6b Staff Agenda Correspondence Page 16
20) It appears that Additive Alternative A contains only the cost of concrete
curbs? Does the estimated cost of Additive Alternative A at $258k include an
estimated cost of installation as well?
a. If the estimated cost of the additive alternative is such a small cost, in
relation to the rest of the cots of the total project, why not include it in
the base bid?
b. Will the project come back to council after the bids are received to
determine whether or not we want to include construction of the
Additive Alternative A?
The estimated cost of Additive Alternative A is approximately $358,000 and
includes materials, installation, and contingency.
These estimates are based on bid results from other cities that have used this
specific type of custom pre-cast concrete curb. Because this product has not been
widely used locally, actual bid costs could vary.
While Additive Alternative A represents a relatively small portion of the total project
cost, staff is mindful of overall project cost, volatility in the local bidding
environment, and limited available funding. Including concrete curbs as a bid
additive provides flexibility to include or omit this feature depending on actual bid
results and funding availability.
Current grant funding does not require a specific separator material, only that the
approved quantity of protected bike lanes be delivered. Therefore, Council retains
flexibility to implement concrete curbs now or in a future phase without risking
current grant funding.
If desired, staff can return to Council for direction prior to construction contract
award, regardless of whether bids allow funding of both the base project and
Additive Alternative A.
ATTACHMENT
A – Updated Higuera Complete Streets Evacuation Study (Dated February 13, 2026)
Higuera Street Emergency Evacuation Analysis
Prepared by:
San Luis Obispo Community Fire Safe Council
Date:
February 13th, 2026
City of San Luis Obispo
Executive Summary
This report evaluates emergency evacuation conditions along the Higuera Street corridor
and assesses the potential effects of the proposed Higuera Complete Street Project on
evacuation performance. The analysis focuses on evacuation clearance time, route
efficiency, and operational constraints under both fire and flood emergency scenarios.
Two evacuation zones, SLO-024 and SLO-025, were analyzed using conservative
assumptions reflecting maximum allowable development and worst-case evacuation
demand.
1. Purpose and Scope
The purpose of this study is to evaluate emergency evacuation conditions along the
Higuera Street corridor and to assess changes in evacuation clearance time, route
efficiency, and operational performance associated with implementation of the Higuera
Complete Street Project. The analysis is intended to support emergency planning,
transportation design review, and environmental documentation.
2. Emergency Scenarios Evaluated
Two emergency scenarios were evaluated independently based on known hazards
affecting the Higuera corridor. Scenarios are not assumed to occur at the same time
Scenario A – Fire or Flooding in San Luis Obispo Creek (Evacuation Zone SLO-024)
This scenario models either a fire or flooding event affecting creek-adjacent
neighborhoods west of Higuera Street. Zone SLO-024 contains mobile home parks,
multifamily areas, and commercial parcels located close to the creek corridor, where
hazards can develop quickly and restrict access.
Flooding may limit creek crossings, reduce roadway capacity, or obstruct access routes.
Fire conditions along the creek corridor can also generate rapid evacuation needs. This
zone relies heavily on Higuera Street as its primary evacuation pathway, making it
sensitive to congestion and roadway constraints.
Scenario B – Wildfire in South Hills Open Space (Evacuation Zone SLO-025)
This scenario evaluates a South Hills wildfire requiring evacuation of the Margarita Area
and surrounding neighborhoods. Zone SLO-025 covers a larger geographic area with
both built and entitled parcels under current land-use designations.
Evacuation performance is influenced by total population loading, merging onto arterial
routes, and traveling distance to safe areas. Compared with Zone SLO-024, the zone
has more route options but a larger number of households, requiring careful modeling of
demand and travel time.
3. Data Sources and Key Assumptions
The analysis uses conservative assumptions to reflect worst-case evacuation
conditions and maximum possible population.
3.1 Roadway Network Data
County roadway centerline and functional classification data were used as the base
transportation network. These were modified to incorporate the proposed Higuera
Complete Street Project, including:
• Reduction to one vehicle lane in each direction (Bridge St. → Margarita Ave.)
• Addition of a continuous center turn lane
• Reduced operating speeds (−5 mph corridor-wide) to represent traffic-calming
features
3.2 Address, Land Use, and Population Data
Residential address data were sourced from City of San Luis Obispo land-use and
zoning datasets. Evacuation demand reflects the maximum population allowed under
existing zones, regardless of whether all units are currently developed. This ensures
modeling accounts for full build-out conditions and long-term emergency planning needs.
3.3 Vehicle Assumptions
A standard assumption of two vehicles per address was applied to all residential units.
This is consistent with regional household vehicle ownership and provides a
conservative planning-level estimate of evacuation demand.
3.4 Mobile Home Parks
Mobile home parks with a single parcel address require manual population estimation.
Each park’s total number of dwelling units was counted using satellite imagery to identify
individual mobile homes, ensuring accurate representation of evacuation demand in
higher-density communities.
3.5 LADRIS Evacuation Modeling Tool
LADRIS (Life and Death Response Information System) served as the modeling platform
for this analysis. LADRIS simulates evacuation behavior by loading population and
vehicle demand onto the roadway network using GIS data, route assignment logic, and
congestion modeling.
It is a planning-level tool designed to compare evacuation performance across
scenarios, not a detailed traffic engineering simulator. LADRIS does not fully account for
traffic signal operations, stop controls, officer-directed traffic, contraflow, or special
evacuation signal timing plans.
Therefore, results represent planning-level estimates intended to guide emergency
preparedness, roadway design decisions, and policy, not precise real-time operational
forecasts.
4. Transportation Network Conditions
Existing roadway lane configurations, intersection geometry, traffic control, and
prevailing operating speeds were assumed for baseline conditions. The primary
evacuation routes for this area are southbound Higuera Street toward Los Osos Valley
Road, northbound Higuera Street toward Madonna Road, eastbound on Tank Farm
Road, and eastbound on Prado Road toward northbound Highway 101. This analysis
also assumes that Prado Road to Highway 101 will be closed during the flooding
scenario.
The Complete Street Project configuration reflects reduced vehicle lanes between
Bridge Street and Margarita Avenue, the addition of a continuous center turn lane, and
an assumed five-mile-per-hour reduction in operating speeds along the Higuera Street
corridor due to proposed traffic-calming and complete street design features such as
speed feedback signs, protected bike lanes, and reduced traffic lane widths.
5. Evacuation Clearance Time Results
Evacuation clearance time represents the total time required for all vehicles within an
evacuation zone to reach a designated safe area under emergency conditions.
5.1 Evacuation Zone SLO-024
Creekside / West of Higuera – Fire and Flood Scenarios
• Total residences to be evacuated: 349
• Total evacuating vehicles: 6,932
Fire Scenario A:
Existing Conditions – Total Evacuation Time: 1 hour 40 minutes
Fire Scenario A:
Complete Street Project – Total Evacuation Time: 1 hour 54 minutes
5.1 Evacuation Zone SLO-024
Flood Scenario A:
Existing Conditions – Total Evacuation Time: 1 hour 47 minutes
Flood Scenario A:
Complete Street Project – Total Evacuation Time: 1 hour 57 minutes
Note: Fire and Flood scenarios use identical demand assumptions. Results differ due to
network constraints, the closure of Prado Rd due to flood history, and routing conditions
specific to each scenario.
5.2 Evacuation Zone SLO-025
South Hills / Margarita Area – Fire Scenarios
• Total addresses to be evacuated: 871
• Total evacuating vehicles: 4,740
Fire Scenario B:
Existing Conditions – Total Evacuation Time: 1 hour 35 minutes
Fire Scenario B:
Complete Street Project – Total Evacuation Time: 1 hour 42 minutes
6. Summary of Evacuation Clearance Times
Evacuation Zone Emergency Type Roadway Condition Clearance Time
SLO-024 Fire Existing 1 hr 40 min
SLO-024 Fire Complete Street 1 hr 54 min
SLO-024 Flood Existing 1 hr 47 min
SLO-024 Flood Complete Street 1 hr 57 min
SLO-025 Fire Existing 1 hr 35 min
SLO-025 Fire Complete Street 1 hr 42 min
7. Conclusions and Key Findings
The analysis indicates that the Higuera Complete Street Project would result in
increases in evacuation clearance times for both fire and flood scenarios within
Evacuation Zones SLO-024 and SLO-025. These changes are primarily associated with
reduced vehicular capacity and lower operating speeds consistent with the project’s
safety and traffic-calming objectives. Importantly, the modeled evacuation clearance
times remain within the City’s two-hour performance benchmark used in recent
evacuation and emergency planning evaluations. With early evacuation activation,
coordinated traffic management, pre-programmed evacuation signal timing, and effective
public communication, the transportation network is expected to continue to function
acceptably under emergency conditions.
End