The Transbay Transit Center will open early next year, but rail service may not arrive for another decade. (Source: TJPA)

The long-awaited Transbay Transit Center is slated to open in downtown San Francisco early next year, but the timeline for bringing Caltrain service to its basement-level train station remains uncertain. Due to skyrocketing costs, a lack of funding, and weak political leadership, the 1.3 mile, $3.9 billion Downtown Rail Extension (DTX) may not be completed for a decade or more. But just because DTX remains in limbo doesn’t mean that Caltrain’s 4th & King Station and the Transbay Transit Center should be disconnected indefinitely. A frequent shuttle service between the two hubs is needed to serve latent demand for better first/last mile access and stronger transit connectivity.

The Transbay Transit Center is located 1.2 miles from Caltrain’s 4th & King Station without a direct transit connection. (Source: SFMTA)

There are many reasons to provide a shuttle connection between the Transbay Transit Center and Caltrain’s 4th & King Station. Each station serves about 30,000 daily boardings and alightings, but the 25 minute walk between the two stations inhibits transfers between AC Transit/WestCAT and Caltrain service. Moreover, there is a bidirectional demand for first/last mile connections to jobs and housing: many Caltrain riders live or work in eastern SoMa, while an increasing number of AC Transit, WestCAT, and casual carpool riders work near 4th & King. The expansion of Caltrain service associated with electrification in 2021 will further grow this demand. While Muni’s 10-Townsend provides some service to these areas, it is not an ideal fit: it does not provide a direct connection to the Transbay Transit Center, operates only every 15 minutes, and is subject to upstream delays in the Financial District and elsewhere. This gap in transit service will persist even after completion of the Central Subway in 2019, which will not stop near the Transbay Terminal.

Given the clear need for a better transit connection between Caltrain and Transbay, the lack of shuttle service is a disappointing result of fractured transit governance. Like DTX, a shuttle connection would benefit several transit agencies across multiple counties (including but not limited to Caltrain, Muni, AC Transit, WestCAT, and BART), but none of these agencies are incentivized to implement such a service. For example, San Mateo County’s Commute.org already operates a $3 million dollar a year Caltrain shuttle program with 20 routes that collectively serve only 2,300 daily passengers. Even though a Transbay-Caltrain shuttle could double Commute.org’s system ridership, the agency has not considered such a service since it would operate outside of their San Mateo County service area. Other agencies share this sense of inertia: the connection would most benefit commuters to/from the Peninsula and East Bay, but occurs wholly within Muni’s service area.

A shuttle connection between the Transbay Transit Center and Caltrain’s 4th & King Station represents an easy win to enhance regional transit service. Better regional coordination is needed to plug this transit gap sooner rather than later.