Transbay Joint Powers Authority outlines funding, schedule for Portal (downtown rail extension)

The Transbay Joint Powers Authority presented an update Thursday to the San Francisco Planning Commission on the Portal, the long‑planned rail connection intended to bring Caltrain and future high‑speed rail into the Salesforce Transit Center.

Adam Vanderwater, executive director of the Transbay Joint Powers Authority, described the Portal as the remaining step in the Transbay program to connect peninsula rail service directly into downtown. The project envisions a new accessible station under Townsend Street and a two‑level train box beneath the transit center that would contain three platforms and six tracks to serve Caltrain and high‑speed rail.

Vanderwater told commissioners the project is currently in the Federal Transit Administration engineering phase and that the FTA last year committed about $3.38 billion through the New Starts program. The agency also counts a prior 2010 investment of roughly $729 million as a local match. Vanderwater said that combination puts the program “over 70% funded,” and that TJPA is working to close the remaining gap through a combination of state contributions, regional allocations and development‑derived funds. He said the agency’s near‑term goal is to sign a full funding grant agreement (FFGA) around 2027, with heavy civil tunneling procurement and construction following if funding is secured.

The project team told commissioners it expects service to the train box in the early‑to‑mid 2030s if funding and schedule remain on track. Vanderwater emphasized the schedule and cost remain funding‑dependent; he also said tunneling methods have been refined to remove about 10% of the previous scope without reducing projected ridership and…