While the East Coast and Midwest have plenty of costly federally funded transit projects, the biggest boondoggles are in Northern California. And, unless Congress starts intervening, billions will continue to flow to overbuilt, low-ridership projects in and around San Francisco.

For fiscal 2024, the Biden administration budget allocated $500 million to a six-mile extension in San Jose, now estimated to cost $12.75 billion. The most recent travel model for this project forecasted only 32,900 weekday riders for the extension, and that was developed with pre-COVID ridership. Actual utilization of the four new stations is likely to be far less.

Subway extensions in New York City are also incredibly expensive, with the first and second phases of the Second Avenue line weighing in at just over $12 billion. But at least they attract riders; once the second phase is finished, the New York MTA expects the line will serve 300,000 daily riders, nine times the number of passengers projected by the San Jose project for about the same cost.

While the Federal Transit Administration prioritizes projects, Congress provides overall funding and could single out projects in authorizing legislation. When House Republicans were in the minority, they successfully pressured Democrats to remove $140 million from the American Rescue Plan earmarked for the San Jose transit project, which they derisively labeled as the “Nancy Pelosi Subway.”

But during this year’s unending budget cycle, the Republican House majority wasn’t able to lay a glove on the costly extension. Appropriators trimmed the Federal Transit Administration’s budget for Capital Investment Grants from $2.85 billion to $2.2 billion. But when combined with $1.6 billion in advanced appropriations from the bipartisan infrastructure bill, the Federal Transit Administration will have plenty of resources to pour into the San Jose project.

President Joe Biden’s 2025 budget has started the ball rolling on yet another Bay Area transit boondoggle that merits congressional attention. The project, known as “The Portal,” is a tunnel that extends Caltrain commuter rail service currently terminating at the edge of San Francisco’s downtown to the more centrally located Salesforce Transit Center. The tunnel adds 1.3 miles to Caltrain at a cost of $8.25 billion, making it the costliest rail project on a per-mile basis ever.

As with the San Jose extension last year, this year’s administration budget includes $500 million for the San Francisco extension as a downpayment toward a multibillion-dollar Full Funding Grant Agreement. The FFGA is currently expected to cover 49% of the project cost, or $4.1 billion.

Although the existing rail terminal is not in the heart of San Francisco’s downtown, it is served by two light rail lines that reach core areas closer to the Salesforce Transit Center. Commuters can also complete their trips by walking, biking, or scootering given the short distances involved.

Project sponsors improbably estimate that 48,000 daily riders will use the extension. Before COVID-19 slashed Caltrain ridership, only 15,000 riders were using the current San Francisco terminal each weekday. Although Caltrain has not published per-station boarding since the pandemic, we know that ridership across the full system fell from about 70,000 in 2019 to about 20,000 now.

For the extension to reach its aggressive ridership projection, San Francisco’s moribund downtown would have to spring back to life, companies would have to unwind their pandemic-era work-from-home policies fully, and California’s High-Speed Rail project would have to be finished so that passengers from central and Southern California could reach the new terminal.

But the high-speed rail project is short about $100 billion of required funding, money that is unlikely to materialize as both the federal and California state governments struggle with large budget deficits.

Indeed, House Republicans recognized that California High-Speed Rail was such a waste that they inserted language into their version of the relevant fiscal 2024 appropriations bill banning further federal support for the project. Although that language did not survive House-Senate negotiations, it shows what is possible.

In an encouraging sign for the fiscal 2025 budget cycle, the Republican Study Committee recently called for the complete abolition of the Federal Transit Administration’s Capital Investment Grants. But if full program abolition is impossible, representatives should grill Department of Transportation officials about the ridership projections and cost of the San Francisco Portal project. If they cannot get satisfactory answers, they should strip funding for this project from the budget and forbid the Federal Transit Administration from shifting around other funds to pay for it.