For years, Randal O’Toole has warned governments that urban rail systems usually make no economic or practical sense. They are more expensive and less flexible than bus systems. But cities keep making wildly optimistic assumptions about rail costs and ridership, and new lines keep getting built. It is a triumph of politics over experience.

The other day, the Washington Post reported ridership data on phase 1 of D.C. Metro’s Silver Line:

But of the five stations that opened in July 2014, only the end-of-line Wiehle-Reston station has come close to projected ridership. At three stops in Tysons — McLean, Greensboro and Spring Hill — ridership is a mere fraction of what planners projected in a 2004 environmental impact report. In May of this year, for example, average daily weekday ridership was 1,618 at the McLean station, slightly below the 1,634 in May 2015 and well below the 3,803 the Silver Line was projected to serve in its first year of operation, according to the 2004 report.

So actual ridership on some parts of this Northern Virginia line are less than half of the original estimate. By the way, the cost of the project ended up almost doubling from what the planners and politicians had promised. Federal taxpayers picked up part of the tab.

Phase 2 of the project is under construction, and it will extend the Silver Line to Dulles Airport, 28 miles from D.C. The project never made sense to me. The airport already has the dedicated and congestion-free Dulles Access Road that connects the airport to the inner suburbs and downtown.

Let’s say you are a NYC businesswomen flying into Dulles for some lobbying in D.C. If you take the rail system, it will probably take you much longer to get downtown than if you took a taxi along the Access Road. Then when you get off the Metro downtown, you may still need a cab to get to your final destination.

Or let’s say you are a Virginia family flying out of Dulles on vacation. Would you want to drive to a Metro station with all your bags, leave your car parked there, and then risk missing your plane by taking the unreliable rail system? I don’t think so. I’ll bet ridership on Phase 2 of the Silver Line will come in low as well.

For decades, federal subsidies have induced state and local officials to build costly and inefficient light- and heavy-rail systems when bus systems and highway expansion generally make more sense. Congress should end the bias in favor of rail by ending federal aid for urban transit, as discussed at DownsizingGovernment.org.