The Pennsylvania Avenue Extension project will support future uninterrupted passenger rail service through San Francisco. The project will place current Caltrain and future California High-Speed Rail passenger rail lines underground, allowing vehicle, pedestrian, and bicycle traffic to flow uninterrupted and improve safety for all road users.
The Transportation Authority is studying potential tunnel alignments that will have trains running underground along Seventh Street and Pennsylvania Avenue, in order to remove existing Caltrain rail crossings at Mission Bay Drive and 16th Street and eliminate the need for traffic to wait while trains cross.
The project, as recommended by the SF Planning Department’s Railyard Alignment and Benefits Study, will be designed to connect to the Downtown Rail Extension, which will bring Caltrain and California High-Speed Rail from 4th and King streets to the Salesforce Transit Center.
The Transportation Authority is closely coordinating the Pennsylvania Avenue Extension work with related initiatives, including the Downtown Rail Extension led by the Transbay Joint Powers Authority, the Southeast Rail Station Study led by the SF Planning Department, and multi-agency planning and coordination for the 4th and King Railyard.
Increase connectivity between Mission Bay, Potrero Hill, and Design District/SOMA neighborhoods
Improve safety of pedestrian, bicycle, and vehicle traffic on surface streets
Enable improved efficiency of Caltrain operations and service planning
Improve quality of life in surrounding neighborhoods by substantially reducing existing congestion and air quality and noise effects associated with existing Caltrain and future rail expansion
Timeline and Status
Summer 2020 to Fall 2021
Development of preliminary technical planning study and preparation of project initiation report
Refinement of alignment alternatives
Preliminary evaluation of constructability, rail operations and interfaces, traffic impacts, utility conflicts, geotechnical and hydrological considerations, cost, schedule, risk, environmental considerations and benefits for feasible alignments
Fall 2021 to Winter 2022
Preliminary public and stakeholder engagement
Presentation of project initiation report and recommendations for next steps
Future Steps (approximately 10 or more years for further project planning, design, and construction)
Further pre-environmental technical analysis; environmental review and preliminary design; final design; procurement and construction
The Transportation Authority is leading the conceptual design study work for the Pennsylvania Avenue Extension in close coordination with:
- Caltrain/Peninsula Corridor Joint Powers Board
- Transbay Joint Power Authority
- City and County of San Francisco
- SF Planning Department
- California High-Speed Rail Authority
- San Francisco Public Utilities Commission
Cost and Funding
The Transportation Authority Board appropriated $1.6 million in half-cent transportation sales tax funds for the current conceptual design study of the project.
Funding for construction will be identified in later phases of work.
Pennsylvania Avenue Extension Tunnel Alternatives Under Consideration
This alternative would provide a tunneled rail alignment (either single bore or twin bores) from Downtown Rail Extension to a point immediately north of Cesar Chavez Street. This long alternative requires replacement of the existing 22nd Street Caltrain Station.
This alternative would provide a tunneled rail alignment (either single bore or twin bores) from Downtown Rail Extension to approximately the site of the existing 22nd Street Caltrain Station. This alignment would require some modifications to the 22nd Street Station.
This alignment would allow for preservation of the existing 22nd Street Caltrain Station, with minor modifications.
The SF Planning Department’s Southeast Rail Station Study is assessing alternative locations for a station in the PAX study area (including the option of retaining the existing 22nd Street Station), as well as sites for a Caltrain Station in the Bayview. The Pennsylvania Avenue Extension may require modification or replacement of the 22nd Street Station, depending on the alternative. The Pennsylvania Avenue Extension concept design work is being coordinated with the development of the Southeast Rail Station Study.