HomeMy WebLinkAboutAttachment E - Transportation Analysis
TRANSPORTATION ANALYSIS
ATTACHMENT E
to the
573 Forbes Boulevard Project Environmental Checklist
573 Forbes
Transportation Impact Analysis
Prepared for:
Vigilant Holdings and City of South San Francisco
September 2023
SF23-1306
Table of Contents
1. Introduction ............................................................................................................................... 1
1.1 Project Description ............................................................................................................................................................... 1
1.2 Thresholds of Significance ................................................................................................................................................ 4
1.3 Report Organization ............................................................................................................................................................ 4
2. Environmental Setting .............................................................................................................. 5
2.1 Roadway Facilities ................................................................................................................................................................. 5
2.2 Transit Facilities and Service ............................................................................................................................................. 5
2.3 Bicycle & Pedestrian Facilities .......................................................................................................................................... 9
2.4 Emergency Response ........................................................................................................................................................10
2.5 Transportation Plans & Policies ....................................................................................................................................11
3. Project Analysis ....................................................................................................................... 13
3.1 Travel Demand .....................................................................................................................................................................13
3.2 Consistency with Plans & Policies ................................................................................................................................14
3.3 Vehicle Miles Traveled ......................................................................................................................................................14
3.4 Site Circulation and Design Hazards ...........................................................................................................................16
3.5 Emergency Vehicle Access ..............................................................................................................................................16
4. Impacts and Mitigations ......................................................................................................... 17
4.1 Consistency with Plans & Policies ................................................................................................................................17
4.2 Vehicle Miles Traveled ......................................................................................................................................................17
4.3 Design Hazards ....................................................................................................................................................................18
4.4 Emergency Access ..............................................................................................................................................................18
Appendix: Local Transportation Analysis ................................................................................. 19
Parking and Site Circulation ...................................................................................................................................................19
Bicycle and Pedestrian Access ..............................................................................................................................................20
Transit .............................................................................................................................................................................................20
Passenger Loading ....................................................................................................................................................................21
Off-Site Traffic Operations .....................................................................................................................................................21
Intersection Traffic Controls ...................................................................................................................................................23
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1. Introduction
1.1 Project Description
This transportation impact analysis (TIA) evaluates potential transportation impacts associated with the 573
Forbes development in South San Francisco, California (referred to as the “Project”). The Project site is
located near the intersection of Forbes Boulevard and Gull Drive and presently has a one‐story 33,250
square foot building occupied by Apex Logistics, a warehousing and logistics company. The Project would
replace the existing land use with an eight story building with 246,234 square feet of office/R&D floor area
and 315,718 square feet of gross floor area including the basement level and associated eight story parking
garage. The proposed parking structure includes 470 proposed stalls and no surface parking.
Figure 1 shows the Project location. Figure 2 presents the Project site plan.
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1.2 Thresholds of Significance
The impacts of the Project related to transportation will be considered significant under CEQA if any of the
following Standards of Significance are exceeded, per Appendix G of the California Environmental Quality
Act (CEQA) Guidelines:
• Conflict with a program plan, ordinance, or policy addressing the circulation system, including
transit, roadway, bicycle, and pedestrian facilities;
• Generate per-employee VMT greater than the City's adopted threshold of 15 percent below the
regional average, according to CEQA Guidelines Section 15064.3, subdivision (b) and City of South
San Francisco Resolution 77-2020 related to VMT;
• Substantially increased hazards due to a geometric design feature or incompatible uses; or
• Result in inadequate emergency access
The criteria of significance apply to all Project scenarios as measured against the corresponding No Project
scenarios.
1.3 Report Organization
This Transportation Impact Analysis includes the following sections focused on topics relating to the CEQA
Thresholds of Significance described in the previous section. These topics are grouped into three sections:
• Environmental Setting: An overview of the existing roadway, transit, bicycle, and pedestrian
networks, along with current transportation plans and policies.
• Project Analysis: A summary of the Project’s transportation demand management (TDM) program,
trip generation, distribution, and assignment, and vehicle miles traveled.
• Impacts and Mitigations: An analysis of the Project’s impacts and mitigations in relation to the
thresholds of significance.
A local transportation analysis is presented in the appendix for informational purposes consistent with the
City of South San Francisco’s Transportation Impact Analysis Guidelines.
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2. Environmental Setting
This section describes the existing transportation and circulation setting near the Project site: the existing
roadway network, transit network and service, pedestrian conditions, bicycle conditions, and emergency
vehicle access.
2.1 Roadway Facilities
The Project site is located on the north side of Forbes Boulevard near the intersection of Forbes
Boulevard/Gull Drive. Regional access to the Project site is provided via US-101 accessed via Oyster Point
Boulevard to the north and East Grand Avenue via Forbes Boulevard to the south. Vehicular access is
provided two driveways along Forbes Boulevard.
The following roadways are located near the Project site:
• Forbes Boulevard is a two- to four-lane street connects East Grand Avenue to the Genentech
Campus via the Project site.
• Gull Drive is a two-lane road connecting Oyster Point Boulevard with Forbes Boulevard to the east
of the Project site. The intersection of Forbes Boulevard/Gull Drive is signalized.
• Allerton Avenue is a two-lane roadway connecting Forbes Boulevard with East Grand to the west of
the Project site. The intersection of Forbes Boulevard/Allerton Avenue is stop controlled.
• Oyster Point Boulevard is an east-west arterial street that connects U.S. 101 with the Oyster Point
Marina. It has four to six travel lanes between Gull Drive and U.S. 101.
• East Grand Avenue is an east-west arterial street connecting US-101 with the Genentech campus.
It has four to six travel lanes.
• U.S. 101 is an eight-lane freeway and principal north-south roadway connection between San
Francisco, San José, and the Peninsula. U.S. 101 is located approximately one mile west of the
Project site and has two primary interchanges at Oyster Point Boulevard and East Grand Avenue.
2.2 Transit Facilities and Service
The Project site is located within walking distance of ferry, shuttle, and bus service, while regional rail service
may be accessed via first/last mile shuttles. Existing transit services are shown in Figure 3 and described
below.
2.2.1 Regional Transit Service
The following transit services operate within South San Francisco and are accessible from the Project site.
• BART provides regional rail service between the East Bay, San Francisco, and San Mateo County.
The South San Francisco BART Station is located approximately 3.5 miles west of the Project site.
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Two BART lines serve South San Francisco Station: the Yellow Line connecting Antioch with San
Francisco International Airport, and the Red Line connecting Richmond and Millbrae. Both lines
travel to the East Bay via San Francsico. Each BART line operates every 15-minutes throughout the
day.
• Caltrain provides passenger rail service on the Peninsula between San Francisco and San José, and
limited service to Morgan Hill and Gilroy during weekday commute periods. The South San
Francisco Caltrain Station serves local and limited trains, with approximately 30-minute headways
during peak times and 60-minute headways during off-peak times. Station access to the East of
101 Area is located at the intersection of East Grand Avenue/Poletti Way. The Caltrain Station is
located approximately 1.2 miles to the west of the Project site. In 2024, Caltrain plans to complete
its electrification project to support the operation of faster and more frequent rail service on the
Peninsula.
• The Water Emergency Transportation Authority (WETA) provides weekday commuter ferry service
between the Oakland/Alameda ferry terminals and the South San Francisco Ferry Terminal. There
are three morning departures from Oakland/Alameda to South San Francisco, and three evening
departures from South San Francisco to Oakland/Alameda. The Ferry Terminal is located
approximately 0.7 miles to the northeast of the Project site.
• SamTrans is the regional bus provider for San Mateo County. SamTrans Route 130 currently
provides service through the East of 101 Employment Area, from the South San Francisco Ferry
Terminal to downtown South San Francisco via Oyster Point Boulevard.
2.2.2 East of 101 Commuter Shuttle Service
Commute.org and Oyster Point Mobility provide weekday commute period first/last mile shuttles
connecting employers with BART, Caltrain, and the ferry. The following shuttles operate near the Project
site:
• Commute.org operates three shuttle routes along Oyster Point Boulevard and three shuttle routes
along East Grand Avenue connecting to the South San Francisco BART station, the South San
Francisco Caltrain Station, and the South San Francisco Ferry Terminal. Shuttles are funded by a
public-private partnership and operated by SamTrans. The nearest shuttle stops are located about
0.4 miles away at the intersection of Oyster Point Boulevard/Eccles Avenue and Cabot Drive/Allerton
Avenue.
• Oyster Point Mobility operates two shuttle routes connecting to the Glen Park BART and Millbrae
Caltrain stations. Shuttles are privately funded and operated. The nearest shuttle stop is located
about 0.4 miles away at the intersection of Cabot Drive/Allerton Avenue; however, new stops are
planned or under construction 0.2 miles away at the intersection of Forbes Boulevard/Allerton
Avenue via nearby development projects.
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Planned Class II Bicycle Lane South San Francisco Ferry Terminal
South San Francisco Caltrain StationExisting Class III Bicycle Route Planned Class III Bicycle Route
Planned Class IV Separated Bikeway Project SiteExisting Class IV Separated Bikeway
0.5 mi
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2.3 Bicycle & Pedestrian Facilities
2.3.1 Pedestrian Facilities
Pedestrian facilities include sidewalks, crosswalks, trails, and pedestrian signals. Pedestrian facilities near the
Project site tend to serve walking trips connecting to shuttle stops, the ferry terminal, and nearby offices
and businesses. The following pedestrian facilities exist near the Project site:
• Forbes Boulevard has a sidewalk on the north side of the street that provides direct pedestrian
access to the Project site. There is no sidewalk on the south side of Forbes Boulevard.
• Gull Drive has a continuous sidewalk along the east side of the street connecting Oyster Point
Boulevard to Forbes Boulevard. There is no sidewalk on the west side of Gull Drive.
• Atherton Avenue has sidewalk on the east and west side of the street along its entire length. At the
intersection of Forbes Boulevard and Atherton Avenue, marked crosswalks exist on the south and
east legs of the intersection.
• A short new multi-use path is under construction along the western frontage of the Project site
connecting to the 499 Forbes development.
2.3.2 Bicycle Facilities
Bicycle facilities consist of separated bikeways, bicycle lanes, routes, trails, and paths, as well as bicycle
parking, bicycle lockers, and showers for cyclists. The California Department of Transportation (Caltrans)
recognizes four classifications of bicycle facilities as described below.
Class I—Shared-Use Pathway: Provides a completely separated right-of-way for the exclusive use of
cyclists and pedestrians with crossflow minimized (e.g., off-street bicycle
paths).
Class II—Bicycle Lanes: Provides a striped lane for one-way travel on a street or highway. May
include a “buffer” zone consisting of a striped portion of roadway between
the bicycle lane and the nearest vehicle travel lane.
Class III—Bicycle Route: Provides for shared use with motor vehicle traffic; however, are often
signed or include a striped bicycle lane.
Class IV—Separated Bikeway: Provides a right-of-way designated exclusively for bicycle travel adjacent
to a roadway and which are protected from vehicular traffic. Types of
separation include, but are not limited to, grade separation, flexible posts,
inflexible physical barriers, or on-street parking.
Current bicycle facilities in the Project vicinity as designated by the Active South City Plan are shown in
Figure 4 and discussed below.
• Forbes Boulevard has Class II bicycle lanes between Allerton Avenue and DNA Way. An extension
of bike lanes between Eccles Avenue and Allerton Avenue is planned.
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• Gull Drive has Class II bicycle lanes between Oyster Point Boulevard and Forbes Boulevard and
provides bicycle connectivity between the Project site to Forbes Boulevard and Oyster Point
Boulevard.
• Allerton Avenue has Class II bicycle lanes from Forbes Boulevard to East Grand Avenue
• A short new Class I multi-use path is under construction along the western frontage of the Project
site connecting to the 499 Forbes development.
Bicyclists traveling from the South San Francisco Caltrain Station and other locations west of US-101
primarily access the Project site from Forbes Boulevard. A trail connection between the intersection of
Forbes Boulevard/Eccles Avenue and the Caltrain station is planned via the Active South City Plan.
2.4 Emergency Response
The City of South San Francisco provides the primary emergency response services to the Project site. The
nearest fire station to the Project is Fire Station 62 located at 249 Harbor Way, approximately 1.2 miles
south of the Project site. The South San Francisco Police Department is located 3 miles to the west of the
Project site at 1 Chestnut Avenue. The Kaiser Permanente South San Francisco Medical Center is located
at 1200 El Camino Real approximately 3.3 miles west of the Project site.
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2.5 Transportation Plans & Policies
2.5.1 General Plan
The South San Francisco 2040 General Plan establishes a vision for the City’s future growth. Its Circulation
Element includes goals, policies, and actions covering topics such as complete streets, vehicle miles traveled,
connectivity, safety, transit, active transportation, TDM, and parking. Each goal is presented in, accompanied
by policies and actions that are particularly relevant the Project:
Table 2.1 South San Francisco General Plan Mobility Goals, Policies, and Actions
# Goal Project-Related Policies & Actions
1
South San Francisco prioritizes safety in
all aspects of transportation planning
and engineering.
Policy MOB-1.2: Strive to reduce vehicle speeds throughout the
city to reduce the frequency and severity of collisions.
Action MOB-1.2.1. Incorporate traffic calming treatments into all
street projects to support lower design speeds.
2
South San Francisco provides a
multimodal network with convenient
choices for everyone.
Policy MOB-2.1: Incorporate complete streets improvements into
all roadway and development projects.
Action MOB-2.1.1: Complete multimodal design and impact
analysis. Ensure that roadway and development projects are
designed and evaluated to meet the needs of all street users, and
that development projects contribute to multimodal improvements
in proportion to their potential impacts on vehicle miles traveled.
Action MOB-2.1.3: Implement Active South City Pedestrian and
Bicycle Plan. All capital improvements and development projects
incorporate bicycle and pedestrian improvements identified in the
Active South City Plan, such as trails, bikeways, bicycle detection at
traffic signals, high-visibility crosswalks, and pedestrian-oriented
site plans.
Action MOB-2.1.4: Implement transit speed, reliability, and access
improvements. All capital improvements and development projects
near regional transit stations or bus/shuttle routes incorporate
improvements to advance speed, reliability, and access, such as in-
lane farside bus stops, bus-only lanes, queue jumps, and
pedestrian/bicycle gap closures.
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3. Project Analysis
This section includes an analysis and findings of Project effects on transportation services and facilities in
relation to the thresholds of significance identified in Section 1.2.
3.1 Travel Demand
Project trip generation was calculated using data from the Institute of Transportation Engineers (ITE) Trip
Generation Manual, 11th Edition with adjustments to reflect local site-specific characteristics. ITE’s Research
& Development site studies (Land Use Code 760) capture a range of comparable office/lab land uses similar
to the Project. However, trip generation studies captured by ITE typically reflect suburban sites with ample
parking and limited TDM requirements, whereas the City of South San Francisco’s parking and TDM
requirements are intended to enforce a lower drive-alone mode share. As noted in Section 2.5.3 and
described in the Project’s TDM Plan, the Project must implement a TDM program sufficient to achieve a
maximum of 60 percent of employees commuting via driving alone. The Project’s proposed parking supply
of 1.5 spaces per 1,000 square feet further reinforces this reduced drive-alone mode share target. Based on
the City of South San Francisco’s Transportation Impact Analysis Guidelines, a reduction of 21 percent was
applied to ITE rates to reflect this drive alone mode share requirement and reduced parking supply.1
As shown in Table 3.1, the Project would generate 1,996 new daily trips, 183 new AM peak hour trips and
173 new PM peak hour trips. After accounting for existing land uses, this would result in a net increase of
1,806 new daily trips, 170 new AM peak hour trips and 154 new PM peak hour trips.
Table 3.1 Trip Generation
Land Use Daily AM Peak Hour PM Peak Hour
Total In Out Total In Out Total
Project (ITE 760)
Up to 257,800 KSF
2,527 190 42 232 35 184 219
TDM Reduction (-21%) -531 40 9 49 7 39 46
Project Trips 1,996 150 33 183 28 145 173
Existing Trip Credit -90 6 3 9 4 5 9
Net New Trips 1,806 144 30 174 24 140 164
All Project vehicle travel would enter and exit the site via Forbes Boulevard. Approximately two-thirds of
vehicle trips are expected to travel to/from the west on Forbes Boulevard connecting to East Grand Avenue,
1 ITE rates reflect the national average drive alone commute mode share of around 76 percent based on survey data
from the US Census and American Community Survey between 2000 and 2019. The City’s 60 percent drive alone
mode share requirement results in a 21 percent reduction over this average mode share.
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while approximately one third are expected to travel to the east via Gull Drive to Oyster Point Boulevard. A
majority of vehicle trips are expected to travel via US-101 to access Oyster Point Boulevard and Gull Drive.
3.2 Consistency with Plans & Policies
The Project is consistent with City transportation plans and policies. The Project would enhance the
streetscape of Forbes Boulevard by widening the northern sidewalk, incorporating pedestrian-oriented
landscaping and lighting, and striping bicycle conflict zone markings at driveways consistent with General
Plan Goals 1, 2, and 5 and the Active South City Plan. A pedestrian and bicycle connection would be provided
to the multi-use trail along the Project’s frontage as well. The Project’s TDM Plan would meet the
requirements of the City’s TDM Ordinance and General Plan Goals 3 and 4 by implementing a TDM program
sufficient to achieve a maximum of 60 percent of employees commuting via driving alone and participating
in annual monitoring efforts. The Project would not exceed the City’s parking maximums consistent with
General Plan Goal 3. The Project has incorporated comments from the City’s site plan review process
consistent with General Plan Goal 4. The Project would not preclude the City from implementing proposed
transportation projects identified in the General Plan or Active South City Plan.
3.3 Vehicle Miles Traveled
The Project’s VMT was analyzed using the City of South San Francisco’s VMT thresholds established in
Resolution 77-2020 on June 10, 2020 and consistent with CEQA Guidelines Section 15064.3, subdivision (b).
The adopted VMT threshold for employment-generating land uses determines that a project would have a
significant transportation impact if its VMT is greater than 15 percent below the baseline for home-based
work (HBW) VMT per employee. Based on the City’s General Plan analysis using the C/CAG Model, this
threshold would be set at 11.6 HBW VMT per employee under existing conditions and 11.3 HBW VMT under
cumulative conditions, as shown in Table 3.2.
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Table 3.2 Home-Based Work Vehicle Miles Traveled Per Employee Thresholds
Scenario Topic Estimated Home-Based Work
VMT per Employee
Existing
Bay Area Regional Average 14.9
Threshold of Significance
(15% Below Regional Average) 11.6
City 16.6
Project1 16.5
Cumulative (2040)
Bay Area Regional Average 14.7
Threshold of Significance
(15% Below Regional Average) 11.3
City General Plan Buildout 13.4
Project1 12.2
1Based on Project’s transportation analysis zone in the C/CAG VTA Model
Source: Fehr & Peers, 2023; C/CAG-VTA Model, 2023.
The Project would exceed the VMT threshold of significance under existing and cumulative conditions as
indicated in Table 3.2. The Project is expected to generate 16.5 HBW VMT per employee under existing
conditions and 12.2 HBW VMT per employee under cumulative conditions. This finding is consistent with
the City’s General Plan EIR (Impact TRANS-1), which concluded that the implementation of land use and
transportation changes in the General Plan would result in VMT in excess of the VMT threshold of
significance. General Plan EIR Mitigation Measure TRANS-1 requires the City to implement a Transportation
Demand Management (TDM) ordinance and revise its parking standards to reduce VMT. The TDM ordinance
was adopted in Chapter 20.400 of the City’s Zoning Code, while revised parking standards are presented in
Chapter 20.330. The Project would implement a TDM program consistent with the TDM Ordinance as
documented in the Project’s TDM Plan and would include a parking supply consistent with the City’s
maximum allowed amount.
Even with the implementation of these policies and mitigation measures, the General Plan EIR concluded
that the City may not reduce VMT below the threshold of significance, citing uncertainty in the cumulative
effectiveness of these measures, as well as unknowns related to transit service levels, transportation
technology, and travel behavior. Because of the programmatic nature of the General Plan, the EIR concluded
that no additional mitigation measures were feasible, and this impact was found to be significant and
unavoidable.
The Project, being consistent with the findings of the General Plan, contributes to this significant and
unavoidable impact to VMT, but would not exacerbate the previously identified impact identified in the
General Plan EIR.. The Project Sponsor shall implement a combination of TDM programs services, and
infrastructure improvements pursuant to Sections 20.400.003 and 20.400.004 of the Zoning Ordinance, such
as: establishing trip reduction programs; subsidizing transit use; coordinating carpooling and vanpooling;
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encouraging telecommuting and flexible work schedules; designing site plans to prioritize pedestrian,
bicycle, and transit travel; and funding first/last mile shuttle services. The Project Sponsor shall be subject
to annual reporting and monitoring.
3.4 Site Circulation and Design Hazards
The Project is located on the north side of Forbes Boulevard to the west of Gull Drive. The Project will
maintain two driveways consistent with the existing site access. The west driveway will serve as the primary
access route for employees and visitors to the Project. The Project’s parking garage and passenger loading
area will be accessed via the western driveway. The eastern driveway will function as the service driveway
to the Project and would primarily be used for deliveries. Driveways along Forbes Boulevard would be
designed with raised pedestrian crossings and green painted bicycle conflict markings consistent with
guidance from the Active South City Plan (see Condition of Approval in the appendix)
Pedestrian and bicycle access to the building lobby will be provided from Forbes Boulevard via a staircase
and accessible ramp, as well as via the trail on the western edge of the Project site. The sidewalk along
Forbes Boulevard would be widened consistent with design guidance provided in the Active South City Plan.
Internal pedestrian circulation would link the passenger loading area and the parking garage. Bicycle
parking would be provided in the parking garage and in front of the building entrance on Forbes Boulevard.
The Project’s site plan is therefore consistent with applicable design standards does not present any
potential design hazards. The Project would not include any uses that are incompatible with the surrounding
land use or the existing roadway system.
The Project would increase vehicle trips along US-101 freeway offramps at Oyster Point Boulevard and East
Grand Avenue. The South San Francisco General Plan EIR (Impact TRANS-4) determined that
implementation of the General Plan is likely to increase vehicle trips on freeway ramps, which could
exacerbate vehicle queues along ramps in excess of their storage capacity and present a potentially
hazardous condition. The Project, being consistent with the General Plan, would contribute to this significant
impact, but would not exacerbate the previously identified impact identified in the General Plan EIR.
3.5 Emergency Vehicle Access
The Project would provide adequate emergency vehicle access consistent with applicable design standards.
Both driveways will accommodate all types of emergency vehicles and meet requirements of the California
Fire Code. Emergency vehicles would access the site via Forbes Boulevard. The Project is not expected to
introduce or exacerbate conflicts for emergency vehicles traveling near the Project site. The Project would
not introduce roadway features that would alter emergency vehicle access routes or roadway facilities.
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4. Impacts and Mitigations
This section includes the evaluation of the Project’s potential impacts under Existing Plus Project and
Cumulative Plus Project conditions. This section also describes the required associated mitigation measures
that would reduce impacts of the Project.
4.1 Consistency with Plans & Policies
Impact TRANS-1: Development of the proposed Project would not conflict with a program,
plan, ordinance, or policy addressing the circulation system and results in a
less than significant impact based on compliance with such plans and policies.
The Project is consistent with City plans and policies as demonstrated in Section 3.5. The Project would
enhance the streetscape of Forbes Boulevard, provide a pedestrian and bicycle connection to the adjacent
multi-use trail, comply with City parking maximums, and implement a TDM program consistent with City
requirements. These measures are consistent with the City’s General Plan, Active South City Plan, and TDM
Ordinance. The Project would not preclude the City from implementing proposed transportation projects
identified in adopted plans. For these reasons, the Project would result in a less than significant impact and
no mitigation is required.
Mitigation Measures: None required
4.2 Vehicle Miles Traveled
Impact TRANS-2: Development of the Project would not exacerbate the previously identified
impacts to VMT identified in the South San Francisco General Plan EIR. (Less
than Significant / Does Not Exacerbate a Previously Identified Impact)
As shown in Section 3.2, the Project would exceed the City’s VMT threshold of significance under existing
and cumulative conditions. This finding is consistent with the City’s General Plan EIR (Impact TRANS-1),
which concluded that the implementation of land use and transportation changes in the General Plan would
result in VMT in excess of the City’s VMT thresholds. General Plan EIR Mitigation Measure TRANS-1 requires
the City to implement a Transportation Demand Management (TDM) ordinance and update its parking
requirements to reduce VMT. The Project would implement a TDM program consistent with the TDM
Ordinance, and would include a parking supply consistent with the City’s maximum allowed amount.
Even with the implementation of these policies and mitigation measures, the General Plan EIR concluded
that the City may not reduce VMT below the threshold of significance, citing uncertainty in the cumulative
effectiveness of these measures, as well as unknowns related to transit service levels, transportation
technology and travel behavior. Because of the programmatic nature of the General Plan, the EIR concluded
that no additional mitigation measures were feasible, and this impact was found to be significant and
unavoidable. The Project, being consistent with the findings of the General Plan, contributes to this
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significant and unavoidable impact to VMT, but would not exacerbate the previously identified impact
identified in the General Plan EIR.
Mitigation Measure: South San Francisco General Plan Update MM TRANS-1 - Transportation
Demand Management. The Project Sponsor shall implement a combination of TDM programs services,
and infrastructure improvements pursuant to Sections 20.400.003 and 20.400.004 of the Zoning Ordinance,
such as: establishing trip reduction programs; subsidizing transit use; coordinating carpooling and
vanpooling; encouraging telecommuting and flexible work schedules; designing site plans to prioritize
pedestrian, bicycle, and transit travel; and funding first/last mile shuttle services. The Project Sponsor shall
be subject to annual reporting and monitoring.
4.3 Design Hazards
Impact TRANS-3: Development of the Project would not exacerbate the previously identified
impacts based on potential design hazards identified in the South San
Francisco General Plan EIR. (Less than Significant / Does Not Exacerbate a
Previously Identified Impact)
As documented in Section 3.4, the Project’s site plan is not expected to pose any onsite design hazards or
incompatible land uses. The Project’s site plan is consistent with applicable design standards and would
provide adequate access and circulation for all modes of travel. The Project would not introduce any new
conflicts or potentially hazardous conditions.
However, the Project would increase vehicle trips along US-101 freeway offramps at Oyster Point Boulevard
and East Grand Avenue. The South San Francisco General Plan EIR (Impact TRANS-4) determined that
implementation of the General Plan is likely to increase vehicle trips on freeway ramps, which could
exacerbate vehicle queues along ramps in excess of their storage capacity and present a potentially
hazardous condition under cumulative conditions. The Project, being consistent with the General Plan,
would contribute to this significant impact, but would not exacerbate the previously identified impact
identified in the General Plan EIR.
4.4 Emergency Access
Impact TRANS-4: Development of the Project would not result in inadequate emergency access.
(Less than Significant)
The Project would provide adequate emergency vehicle access consistent with applicable design standards.
Both driveways will accommodate all types of emergency vehicles accessed via Forbes Boulevard. The
Project is not expected to introduce or exacerbate conflicts for emergency vehicles. Therefore, the Project
would not result in inadequate emergency vehicle access, and the Project’s impacts to emergency access
would be less than significant under Existing Plus Project conditions and less than significant under
Cumulative Plus Project conditions.
Mitigation Measures: None required
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Appendix: Local Transportation
Analysis
This section evaluates the Project’s effects on the local transportation network consistent with the City of
South San Francisco’s Transportation Impact Analysis Guidelines for Tier 3 projects. This analysis is provided
for informational purposes and is not associated with CEQA thresholds of significance.
Parking and Site Circulation
The Project meets City parking requirements.
The Project’s proposed parking supply meets the parking maximums for R&D and office building space set
forth in Table 20.330.004 of the South San Francisco Zoning Code. The Project proposes a parking supply
of 1.5 parking spaces per 1,000 square feet of gross floor area consistent with the maximum parking allowed
for R&D uses.
The Project may occasionally cause vehicle queues to spill back onto Forbes Boulevard for the
eastbound left turn movement.
The median of Forbes Boulevard currently
alternates between landscaping and a
bidirectional left turn pocket. The median left
turn lane accommodates a single vehicle
turning left into Project’s western driveway
while access to the eastern driveway overlaps
with the eastbound left turn lane for the Forbes
Boulevard/Gull Drive intersection. Most
vehicles would use the western driveway, while
freight deliveries would primarily use the
eastern driveway.
Project-related vehicle travel may cause
queues to occasionally spill back onto Forbes
Boulevard for both driveways. At the western
driveway, the 95th percentile queue under existing plus project conditions is expected to be about one
vehicle, which can be accommodated within the existing median. At the eastern driveway, larger trucks
would not have sufficient queueing capacity within the left turn pocket, but the low frequency of deliveries
would cause limited blockages. However, as traffic volumes grow along Forbes Boulevard due to the
cumulative effects of nearby development, the frequency of spillover queues blocking eastbound traffic
may increase.
Existing median and western driveway along Forbes Boulevard
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Condition of Approval – Project Access Improvement: As a condition of approval, the Project shall
modify Forbes Boulevard to accommodate Project-related circulation needs. These changes shall include
the realignment of medians to match Project driveways, expansion of left turn capacity for the western
driveway, addition of a marked crossing for access to the adjacent Class I trail, inclusion of raised sidewalk
crossing and green bicycle conflict zone markings at the Project’s driveway, and modification of lighting
and landscaping as necessary. The Project shall be responsible for the design and construction of these
changes, which shall occur prior to receiving a certificate of occupancy.
Bicycle and Pedestrian Access
Development of the Project would limit driveway conflicts between vehicles, pedestrians, and
bicyclists.
The Project’s site plan would incorporate pedestrian and bicycle enhancements to reduce the risk of conflicts
between pedestrians and bicyclists. The existing sidewalk on the north side of Forbes Boulevard is five feet
wide, while the adjacent Class IIB buffered bike lane is eight feet wide but lacks conflict markings at
driveways. The Active South City Plan’s Bicycle & Pedestrian Design Guide recommends a minimum sidewalk
width of six to eight feet accompanied by a buffer zone width of four to six feet (which may also function
as sidewalk or as landscaping, for a total of 10 to 14 feet). At driveways, the Plan also recommends sidewalk-
level pedestrian crossings and green conflict zone markings for bicycle lanes in order to prioritize pedestrian
and bicycle travel. The Project would incorporate these recommendations by widening sidewalks to X feet
and incorporating bicycle lane conflict zone markings and sidewalk-level pedestrian crossings at driveways.
The Project provides adequate bicycle parking.
The Project proposes to provide short-term and long-term bicycle parking spaces consistent with the City
code requirements. The City’s Zoning Code (Section 20.330.007) requires two types of bicycle parking: “short
term” spaces that typically consist of racks within 50 feet of a main building entrance, and “long term”
spaces that consist of lockers, fenced, or guarded parking. The City requires short term parking is supplied
at a rate of five percent of the total auto parking supply, and long-term parking is supplied at a rate of five
percent of the total auto parking supply. The Project would provide 24 short term spaces located at
placeholder and 24 long term spaces located at placeholder consistent with City requirements.
Transit
The Project does not result in a deficiency in transit service, transit access, or transit operations.
The Project would not affect existing transit facilities or introduce conflicts with existing transit services. No
transit services are present along Forbes Boulevard along the Project’s frontage.
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Passenger Loading
The Project does not result in a deficiency in passenger loading operations.
The Project provides on-site passenger loading space for approximately four vehicles along the main
driveway in front of the building entrance. Passenger loading activities are not expected to interfere with or
spill over onto the Project’s driveway or pedestrian/bicycle facilities.
Off-Site Traffic Operations
The Project does not result in a substantial increase in vehicular delay at intersections near the
Project.
The City of South San Francsico no longer has a Level of Service (LOS) standard for auto operations. Instead,
General Plan Policy MOB-3.2 directs the City to “optimize traffic operations on City streets while avoiding
widening roadways or otherwise pursuing traffic operations changes at expense of multimodal safety,
transit reliability, or bicycle and pedestrian comfort.” This section provides an analysis of the Project’s effects
on traffic operations and potential changes to address any deficiencies consistent with Policy MOB-3.2.
Assumptions and Methodology
The City’s Transportation Impact Analysis Guidelines directs Tier 3 projects to assess the effects on traffic
operations for intersections adjacent to the Project site. Two intersections in the vicinity of the Project were
evaluated: Forbes Boulevard/Allerton Avenue and Forbes Boulevard/Gull Drive.
The Project’s effects on off-site traffic circulation were assessed using Synchro traffic analysis software.
The method from Chapter 19 of the HCM 6th Edition bases signalized intersection operations on the
average control delay experienced by motorists traveling through it. Control delay incorporates delay
associated with deceleration, acceleration, stopping, and moving up in the queue. This method uses
various intersection characteristics (such as traffic volumes, lane geometry, and signal phasing) to estimate
the average control delay.
Table 3 summarizes the relationship between average delay per vehicle and LOS for signalized intersections
according to the HCM 6th Edition.
Traffic conditions for the unsignalized intersections were evaluated using the method from Chapters 20
and 21 of the HCM 6th Edition. With this method, operations are defined by the average control delay per
vehicle (measured in seconds) for each stop-controlled approach that must yield the right-of-way. At
four-way stop-controlled intersections, the control delay is calculated for the entire intersection and for
each approach. The delays and corresponding LOS for the entire intersection are reported in
Table 3 summarizes the relationship between delay and LOS for unsignalized intersections.
Table 3: Signalized Intersection LOS Criteria
LOS Description Average Delay Per
Vehicle (Seconds)
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A Operations with very low delay occurring with favorable progression and/or short
cycle length. ≤ 10
B Operations with low delay occurring with good progression and/or short cycle lengths. > 10 and ≤ 20
C Operations with average delays resulting from fair progression and/or longer cycle
lengths. Individual cycle failures begin to appear. > 20 and ≤ 35
D
Operations with longer delays due to a combination of unfavorable progression, long
cycle lengths, or high volume-to-capacity (V/C) ratios. Many vehicles stop and
individual cycle failures are noticeable.
> 35 and ≤ 55
E Operations with high delay values indicating poor progression, long cycle lengths, and
high V/C ratios. Individual cycle failures are frequent occurrences. > 55 and ≤ 80
F Operation with very high delay values to most drivers occurring due to over saturation
poor progression, or very long cycle lengths. > 80
Source: Transportation Research Board, 2016. Highway Capacity Manual 6th Edition
Table 4: Unsignalized Intersection LOS Criteria
LOS Description Average Control Delay
Per Vehicle (Seconds)
A Little or no traffic delays. ≤ 10
B Short traffic delays. > 10 and ≤ 15
C Average traffic delays. > 15 and ≤ 25
D Long traffic delays. > 25 and ≤ 35
E Very long traffic delays. > 35 and ≤ 50
F Extreme traffic delays with intersection capacity exceeded. > 50
Source: Transportation Research Board, 2016. Highway Capacity Manual 6th Edition
Analysis Scenarios
The effect of the Project on the surrounding transportation system were evaluated for existing (2023)
conditions and existing plus Project conditions. Existing conditions represent the baseline condition upon
which the Project’s effects are measured. Existing plus Project conditions represent the baseline condition
with the addition of the Project. Traffic volumes for existing plus Project conditions include existing traffic
volumes plus traffic generated by the Project. Existing plus Project conditions were compared to existing
conditions to determine potential Project-related effects.
Analysis Results
The Project would not substantially change control delay at the study intersections, with most maintaining
the same LOS conditions after addition of Project trips. Table 5 presents the traffic delay analysis for the
four study intersections under existing and existing plus Project conditions. Both intersections maintain LOS
A or LOS B conditions. No improvement measures are recommended.
Table 5: LOS Results
Intersection Control Type Peak Hour Existing Existing Plus Project
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Delay1 (s) LOS Delay1 (s) LOS
Forbes Boulevard and
Allerton Avenue All Way Stop Controlled
AM 12.1 B 14.2 B
PM 10.1 B 10.5 B
Forbes Boulevard and
Gull Drive Signalized
AM 12.0 B 12.3 B
PM <10 A <10 A
Source: Fehr & Peers, 2023
Intersection Traffic Controls
The Project does not trigger a peak hour traffic signal warrant at the Forbes Boulevard/Allerton
Avenue intersection.
The intersection of Forbes Boulevard/Allerton Avenue is presently all-way stop controlled. The intersection
does not presently meet peak hour signal warrants based on the California Manual on Uniform Traffic
Control Devices. However, recent transportation studies such as the South San Francisco General Plan and
Genentech Master Plan EIR have identified the installation of a traffic signal at this intersection as a long-
term need as the area develops. A traffic signal has also been identified in the City’s Transportation Impact
Fee at this location.
The addition of Project-related vehicle trips would not trigger a peak hour traffic signal warrant at the Forbes
Boulevard/Allerton Avenue intersection under existing plus Project conditions during the AM and PM peak
periods. No improvement measures are recommended.