One third of the MBTA’s outstanding debt, about $1.7 billion, comes from transit projects built by the state as part of a court-imposed mitigation for extra Big Dig traffic; interest on this debt is about two-thirds the agency’s total present deficit. Metra was prepared to pay for a project to rebuild rail bridges that would increase clearance below for trucks and cut the right-of-way’s width from three to two tracks. Rhode Island is spending $336 million on extending the Providence Line to Wickford Junction, with most of the money going toward building parking garages at the two new stations; Wickford Junction, in a county whose number of Boston-bound commuters is 170, is getting 1,200 parking spaces.

Supporters of transportation alternatives talk about the inequity between highway and transit funding in the US, but what they’re missing is that the transit funding bucket includes a lot of things that are manifestly not about transit. At their best, they are parking lots and other development schemes adjacent to train stations, which would’ve been cheap by themselves. At their worst, they are straight highway projects, benefiting road users only.

The situation in Boston, while unique in its brazenness, is not unique in concept. In the US, where there are no pollution taxes on fuel, the only way to mitigate air pollution is by regulation and by building alternatives simultaneously. Put another way, combined highway and transit construction is in most cases not really a combined project; it’s a highway project, plus required mitigation. Requiring the transit agency to shoulder the debt and the operating subsidies is exactly requiring transit users to pay for highways. It’s equivalent to charging transit multiple dollars per gallon of gas saved from any mode shift. And it may get even worse: the proposed House transportation bill includes a provision to allow spending national air pollution control funds on regular highway widening, in addition to the current practice of spending them on carpool lanes.

Historically, the diversion of funding from transit to roads took such insidious forms. For an instructive example from Owen Gutfreund’s book, roads advocates fought to get driver’s license fees and even inspection fees for fuel trucks recognized as road user fees, whose proceeds must be diverted toward roads. For another example from the same book, in Denver, the streetcar system was required to cover 25% of the cost of road maintenance on one-way streets and 50% on two-way streets, and as car traffic rose, streetcars both became slower and had to send over more money toward roads.

Another instructive case study is grade separations. It is to my knowledge universal that expressways and high-speed railroads, both of which must be grade-separated, pay for their own grade separations. In all other cases, who pays is determined by which mode is more powerful, and in the US, this is roads. As the national highway system was built in the 1920s, interurban railroads were required to pay for grade-separations, even when the rail came first. The practice continues today: in Kentucky, the railroad has to shoulder the full cost if it’s from 1926 or newer (Statute 177.110), and half the construction cost and the full planning cost if it’s older (177.170). In contrast, in Japan, grade separations are considered primarily a road project, and so the Chuo Line track elevation project was paid 85% by the national and city governments and only 15% by JR East (page 36). The segment in question of the Chuo Line was built in 1889; I believe, but do not know, that new rail construction in Japan is always grade-separated, at the railroad’s expense.

The situation in the US today is a surreptitious underfunding of transit, and at the same time a surreptitious overfunding of roads. It is not subject to democratic debate or even to the usual lobbyist funding formulas, but, like the obscure regulations that impede good passenger rail, hidden in rules nobody thinks to question. To pay for road mitigations and for parking, transit agencies will cut weekend service and reduce frequency. It’s bad enough when done in the open, but it’s done while claiming that transit is too expensive to provide.