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The best time to build the Downtown Rail Extension was decades ago. The second-best time is now

Illustration by Mia Carson

Tom Radulovich is the Executive Director of Livable City.

Imagine a weekday commute several years from now. You live on the Peninsula and are headed to work in Downtown San Francisco on Caltrain. The first dozen miles of your trip are great. You’re riding in a brand-new, bi-level railcar with ergonomic seats and wifi. Several hundred people are on the train with you, and everyone has a seat. It’s electric-powered, clean and quiet. The tracks have been separated from auto traffic, so it’s fast and reliable. Trains turn up frequently enough during commute times that you don’t always look at the schedule.

The last mile of your commute is a different story. You’re dropped off at Fourth and King streets, a mile from the Downtown core and a mile from BART at a notorious chokepoint in Muni’s streetcar service. Assuming the Central Subway has opened, connecting Caltrain to Union Square via Fourth Street, that means a walk of several hundred feet to reach BART or the Muni Underground at Market Street, just to transfer to another crowded train and complete the trip.

The proposed extension of Caltrain Downtown to the Salesforce Transit Center will close the gap. The Downtown Rail Extension (DTX) is the single most important unfunded transit project in the Bay Area and the one missing link with potential to take the region’s transit network from good to great. 

DTX will link the region’s two largest cities’ downtowns to one another with fast, frequent, clean and high-capacity rail rapid transit—the Bay Area’s first regional metro. It will connect dozens of small to medium-sized downtowns and urban neighborhoods in between and serve both SFO and San Jose’s airport. 

Politicians, most of whom seldom if ever use public transit, often get more excited about transit mega-projects than operations and maintenance. We transit riders get frustrated by inattention to improving transit’s day-to-day workings. All that said, sometimes really big projects— expensive, time-consuming and potentially disruptive—are crucial regional investments. 

The extension to the Salesforce Transit Center will bring Caltrain within a short walk of Market Street transit, including BART, Muni Metro and dozens of Muni bus lines, along with AC Transit’s Transbay buses and Golden Gate transit buses to the North Bay. The Transbay District has grown into one of the densest employment concentrations on the continent, with more office and residential high-rises under construction or planned.

Since the Downtown extension involves a long tunnel to an underground station, it necessitates replacing Caltrain’s diesel locomotives with electric trains (a massive project that will be completed in 2024).

Caltrain modernization will bring the railway from 1930s to 21st-century standards. It will also enable Caltrain to become the region’s first regional metro service. Regional metro, like Paris’ RER or the London Overground, combines elements of an urban metro—frequent, all-day service, level boarding, proof of payment—at a regional scale, by including passing tracks that accommodate express and skip-stop services for long-haul trips without sacrificing local service. 

Our new-and-improved Caltrain will do what BART cannot. BART has some elements of a regional metro, but was built without passing tracks for express trains. BART is also not interoperable with any other rail; it was built with a gauge (the distance between tracks) that’s unique in North America, along with several other design idiosyncrasies. Consequently, intercity and high-speed trains can never use BART’s tracks to get anywhere. Caltrain is being designed to allow rail rapid transit service comparable to BART for the fast-growing eastern side of San Francisco and the Peninsula, while accommodating regional express trains and future high-speed intercity trains which will connect the region to the rest of the state.

The Downtown extension will address a major deficiency in the Bay Area’s rail network: too few, and poorly connected, rapid transit lines in the region’s urban core. Rapid transit and regional rail don’t connect in Downtown San Francisco or Downtown Oakland. 

We have made billions of dollars in public investments in both the Salesforce Transit Center and Caltrain modernization, and the Downtown extension will leverage those to create a truly interconnected regional rail network. But it will still be costly. In 2016, the San Francisco County Transportation Authority estimated the project will cost $3.9 billion. It will likely cost more, since construction cost inflation has continued rising several times faster than the consumer price index (CPI). 

Anti-transit arguments have been given new life by the tech industry hype machine. Driverless cars, or even Tesla tunnels, will, we are told, replace public transit in the near future. But these variants on the private car share many of the disadvantages of conventional cars. Cars require huge amounts of space, as well as energy and resources, to move a single person, and space is at a premium in cities. Innovation is essential, but you can’t run a civilization on vaporware. Trains remain the killer app for urban mobility.

However the pandemic and its aftermath have us asking questions about the future of work, and of office districts like Downtown San Francisco. Will virtual everything and remote work make commuting to work and school obsolete? What if office workers only go in a few days a week? What transit infrastructure will we need in such a future—and what is the future of downtown office districts in that future?

So should the city now commit to raising and spending the billions to bring Caltrain to Downtown? History can be a guide here. Dozens of cities have built city-center rail hubs and converted commuter lines to regional metros. Not one has regretted doing so. Many have predicted this-or-that technological advance will make dense, walkable and transit-served urban neighborhoods obsolete. None have. U.S. cities that let their rail transit networks die mostly regret doing so, and many have been rebuilding them at considerable cost. Cities outside the U.S. kept investing in rail transit and improving connections, and enjoy lively city centers and more mobility options.

Now imagine a few years have passed since your mid-2020s commute. That same comfortable train coach carries you past Fourth and King, which may now be now an underground station. Some people get on and off there, but most of the folks on board ride one more stop to Salesforce Transit Center. It’s bustling. People are transferring between the underground train station, elevated bus station and Muni buses at street level. A concourse-level pedestrian tunnel connects you to Embarcadero Station. The sun is streaming into the high-ceilinged spaces. 

It’s ready for even more passengers once high-speed service to the Central Valley and Southern California starts rolling in a few more years. People are making all different kinds of trips: from home in the Bayview to school in Berkeley, or from home in Emeryville to a job in South San Francisco. All these great transit connections have reduced auto traffic Downtown. You’re exiting the station, taking a short walk to your office, and it’s lovely to walk in the fresh air.

Read a counterpoint to this Perspective by Reason Foundation senior policy analyst Marc Joffe: SF’s Proposed Downtown Railway Extension Is an Unnecessary Boondoggle

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