According to a new report from Reconnecting America, cities and metro areas around the country have about $248 billion worth of transit projects plopped on the drawing board. So what's the holdup? Well, it's not always easy to get funding from Congress. About 80 percent of federal transportation money goes toward highways, leaving just 20 percent for transit. Most of that, meanwhile, is spent on maintenance and buses, leaving just $1.6 billion a year for brand-new projects. And the feds typically pick up half the tab for new transit schemes, so at that rate, most people reading this blog will be dust and bones by the time all those proposed trains and streetcars are finally chugging. And that's just the first hurdle:

Ironically, the increased demand for transit has made it more difficult to win federal funding for projects. Congress has provided more money for transit during the past decade, but available funding has been outstripped by the increased demand. The Federal Transit Administration, in response, has made the federal funding process ever more competitive in order to ensure that only the best projects get funded. The result, however, is a longer and more difficult process that drives up the cost of projects, with the result that there are fewer projects in the funding "pipeline."

The federal funding process for highways is much quicker and easier than the process for transit, and the amount of money that the federal government provides for each road project—called "the federal match"—Is typically much greater. Federal statute requires local governments to put up 20 percent of the funding for most road and transit projects—called "the local match." But road projects receive a much larger federal match—sometimes more than 80 percent—while the federal match for transit was decreased from 80 percent to 60 percent in 2004, and now averages about 50 percent.

The relatively low level of transit investment in the U.S. stands in sharp contrast to funding in other parts of the world. China, for example, is dedicating $88 billion for the construction of 1,062 miles of rail from 2001 through 2015. India has announced it will spend $56 billion to expand its rail system over the next five years. Over the 12-year period covered by the last two federal transportation bills the U.S. dedicated about $19 billion for new construction.

Not only that, but transit projects typically have to undergo intensive scrutiny: a cost-benefit analysis, a land-use analysis, an environmental-impact analysis, and, usually, a detailed comparison among various alternatives. That all sounds reasonable, except that highway projects don't have to suffer through any of this, save for a (looser) environmental-impact analysis. Highway money is basically a gift to states and local governments, and, not surprisingly, most communities find it easier to build new highways than to fund, say, light-rail, no matter how popular the latter might be.

At this point, one common response is that roads pay for themselves—via the gas tax—while mass-transit projects don't, so we should be funding far more of the latter. Two responses: 1) That's not quite true; roads don't entirely pay for themselves, and 2) even so, mass-transit projects provide all sorts of external benefits for both public health, the environment, and energy security that there's an excellent case for subsidizing them to a greater extent than we currently do. (I'm also curious to see what sort of economic benefits might come from linking cities via high-speed rail rather than clogged highways.) Obviously we'll always need new roads, but there's no reason the ratio has to be quite as lopsided as it has been historically, especially in an age where we're trying to curtail oil consumption.

--Bradford Plumer