South Linden
Avenue and
Scott Street
Grade
Separation
(LSGS)
February 12, 2025
1 Objective
3 Provide City Council with an Update on the South Linden Avenue and Scott Street Grade Separation Project and Seek Direction on the Optimized Alternative
Background / Discussion
5 Planning Phase (Project Study Report) - Completed 2021 PSR - Alternative 1 selected
• Combination – Rail Elevated by 15' & Road Lowered by 7' • Provide Grade Separation at South Linden Avenue for:
• Rail Tracks / Vehicle Lanes / Bike Lanes / Pedestrian Walkway • Scott St. in San Bruno closed. Replaced with pedestrian underpass Preliminary Engineering / Environmental Phase – Started 2023 • Grant Funding from SMCTA
• Caltrain Retained RSE (Design Consultant) in 2023
• Caltrain / RSE first Task – Perform Value Engineering • Caltrain to Present Results of first Task
Stakeholders Logo and Roles
6 Lead Implementing Agency
Primary Funding
Agency Project Sponsors
Forecast Gate Down Times at Peak Hours
(Long Range Service Vision – Adopted Moderate Growth Scenario) 7 Trains will be passing through the grade crossing every few minutes.
Information from City of San Bruno City Council Meeting Presentation on November 29, 2019.
Project Location/Key Features
South San Francisco Station
Colma Creek
N
San Bruno Station
City Limit SSF and SB
Scott St
1,850 feet
to San Francisco to San Jose
South Linden Ave
Southline
Development
I-380
UPRR/
Granite Rock
8 Scott Street
9 Scott St
AT&T
Parkin
g Lot
Southline
Developmen
t
Airgas
Storage
Granite
Rock
Central
Concrete
S. Linden Street
N
N
10 History
Project Study Report (PSR)
Alternative 1 Development Process
PSR Alternative 1 was selected by the SSF City Council and San Bruno City Council in August/September 2020 after a three-year process involving stakeholders in the project area and presented four design alternatives for consideration.
11 The four design alternatives include:
• Alternative 1: Rail Partially Elevated and Roadway Partially Lowered • Alternative 2: Rail Partially Lowered and Roadway Partially Elevated • Alternative 3: Rail At-Grade and Roadway Lowered
• Alternative 4: Rail At-Grade and Roadway Elevated
PSR Alternative 1 Requirements
12 ❑ Lowering Roadway 7 ft, elevate railroad
15 ft. and build railroad bridge.
❑ Elevating Caltrain tracks for one mile
with retaining walls
❑ Electrified shoofly (detour) tracks with
❑ Significant property and partial buildings
acquisition/modifications
❑ Relocation of UPRR/Granite Rock
tracks plus fiber optic and utilities
❑ Shoofly and railroad construction within
safety envelope of operating electrified
trains
Alternative 1: Hybrid
Rail Partially Elevated and Roadway Partially Lowered
South Linden Avenue
Rail Elevated 15 ft
Roadway Lowered 7 ft
PSR Alternative 1 –Design Footprint
5600 ft
Rail Elevated – 15 ft
Road Lowered –7 ft
13 14
PSR Alternative 1
Challenges
PSR 1 Alternative Challenges
❖ Original Project Study Report (PSR) from 2020 focus:
❑ Preliminary Engineering Design Only
2024 effort discovered new issues on PSR 1:
➢ Building the PSR Alt 1 is now estimated to take up to seven years ➢ Building the PSR Alt 1 presents several high-risk challenges ❑ Very limited access to the construction site
❑ Larger footprint due to shoofly and elevated tracks
❑ Safety requirements related to construction near tracks ❑ Extended duration increases costs, potentially impacting project fundability ❖ Recent value engineering effort focus: Constructability 15 PSR1 Stage 3C – Construct Final Main Tracks
16 Construction of track
and electrification
between retaining walls
17 Order of Construction
JPB
ROW
39.5’
TCE
JPB
ROW
Final Caltrain Tracks
the Caltrain tracks and
OCS are constructed
UPRR/Granite Rock
Tracks
require relocation
prior to construction
Shoofly Tracks
removed at the
end of construction
18 Value Engineering
and Optimized
Alternative
Construction Methodology Re-evaluation
In 2023, a new design consultant was tasked with performing value engineering (VE) and a review of the PSR Alternative 1 design, focusing on constructability, verifying construction cost and related risks with the preferred alternative.
The consultant took a deeper dive into:
❑ Constructability – Staging, sequencing, and duration
❑ Environmental
❑ Utility Relocations
❑ Traffic impacts
❑ Compatibility with Caltrain operations and electrified corridor 19 Optimized Alternative (OA)
20 Airgas
S. Linden Ave
Westside Materials
Central Concrete
The evaluation revealed a refinement of the
PSR alternative. A “jacked box” or Optimized
Alternative that has the following
characteristics and advantages:
❑ Retains key features of S. Linden
Grade Separation
❑ Lower risk (due to less ROW, no
track impacts to UPRR/Granite Rock,
fewer environmental impacts, faster
construction)
❑ Fewer railroad operational impacts
❑ Lower total project cost
PSR Alternative 1 –Design Footprint
5600 ft
Rail Elevated – 15 ft
Road Lowered –7 ft
21 Optimized Alternative – Design Footprint
Rail Elevated – 2 ft
Road Lowered – 20 ft
22 Box Jacking
❑ Push or "jack" a precast concrete box beneath existing tracks ❑ Keeps existing railroad tracks
❑ Eliminates shoofly and elevated tracks
23 Similar Project – Jefferson Avenue in
Redwood City
24 ❑ Road lowered 24 ft
❑ Track kept at existing
elevation
❑ Fully accessible for
peds/bikes/autos
❑ Retaining walls allow for
building construction and
landscaping
25 PSR Alternative 1
vs
Optimized Alternative
Design Alternative Comparison
26 Project Aspect PSR Alternative 1 Optimized Alternative Construction Schedule 84 months 36 months
Estimated Total Project Cost $450M ~28% less than PSR1
Risk High Low
Environmental Impacts High Low
Road Closures / Traffic Impacts Long duration Moderate duration Operational Impacts (RRs) Extensive Minimal
Project Footprint Impacts Extensive Moderate
1 Dollars shown are in millions and based upon 2024 estimates. 2 Based upon escalation of 5% to midpoint of construction in year 2032 1,2
Project Development Timeline
27 Caltrain Lessons Learned
• Educate and inform stakeholders on the evolving landscape of commercial cost estimates to ensure alignment and informed decision-making.
• Strengthen early collaboration with industry experts to obtain feedback on constructability, construction schedule, sequencing, and commercial cost estimates before finalizing designs, to support decision-making and improve cost certainty.
• Foster collaboration among all technical project stakeholders to identify and implement valueengineering solutions, while establishing clear timelines for next steps and decision-making. • Develop and solidify a strategic approach for securing sufficient funding and approvals to advance enabling work to mitigate project delays and cost escalations. • Implement consistent and transparent oversight framework on multiparty projects to support timely and durable decision-making.
• Developed and implemented a Corridor Crossing Strategy & Delivery Guide 28 Summary
With new analysis of the design, constructability, and risks, Caltrain endorses the Optimized Alternative as a more effective and realistic option to advance forward with design.
By contrast, the PSR Alternative is a less practical alternative due to:
➢ approximate 7-year construction duration
➢ the large impacts (ROW, the environment, the footprint, traffic) ➢ the higher cost, higher risk, and less fundability
➢ the impacts of safety clearances
➢ the construction inefficiencies (constrained site access, electrified operating railroad environment)
29 Recommended Action
30 Staff Recommendation is to proceed with the Optimized Alternative Pre
Next Steps
31 • Continue with the Preliminary Engineering (up to 35%) • Continue development and minor refinements of the OA
design and agreements
• Continue outreach and gather feedback from Caltrain, city managers, and other stakeholders
• Start the Environmental Review Process
• Project Sponsors to Seek Funding for Remaining Phases of Design
Questions / Action
32