The Way Congress Has Funded Transportation Since 2008 Is Not Entirely Legal

The Highway Trust Fund that pays for America's highways (and some of its mass transit system) is going broke. And it turns out that by incrementally saving the fund from financial failure, Congress might also be breaking the law.

From 2008 through September 2014, the Highway Trust Fund received at least $52 billion in transfers from the general treasury—about 17 percent of its total revenue during that period. That means only 83 percent of the fund's receipts have come from user-related taxes; namely, the federal gas tax. But a Congressional budget act from 1974 requires all federal funds that work on contract authority, such as the Highway Trust Fund, to pull at least 90 percent of receipts from user expenses. Strictly speaking, then, federal transportation funding has been in violation of this mandatory threshold for years.