Gas tax falling short in paying for transportation needs
USA Today - 02/24/2012
The USA is at a critical juncture in how it pays for roads, bridges and transit. That’s because the federal tax on gasoline, the primary method since 1956, has lost one-third of its buying power since it was last raised in 1993. States add their own tax on top of that, but the federal tax accounts for about 45%-50% of capital spending for transportation.