In the nation's capital, a deadly subway car crash last week served as a reminder of some serious problems plaguing the country's transportation system. Trains, as well as roads and bridges, are in need of repair, but a government fund that pays for major projects is running out of money, and a law that governs transportation policy is expiring in October.

With this latest crash as the backdrop, Congress and the White House are squabbling over transportation, hoping to work out some differences. NPR's Audie Cornish reports.

AUDIE CORNISH: In less than 60 days, the Highway Trust Fund will likely run out of money. States rely on the fund to pay for road and transit projects, but the fund relies on gasoline taxes, 18.4 cents per gallon since 1993. And those revenues are falling because of inflation, the slow economy and the rise of more efficient cars.

It translates to a shortfall of billions of dollars, says Transportation Secretary Ray LaHood.