Question: A Bridge Too Far Gone Gas taxes have paid for most of the American highway system. Now motorists pay about one-third as much in the gas taxes to drive a mile as they did in the 1960s. Raising gas taxes is politically tricky, but it wouldn't matter if private cash were flooding into infrastructure, or if new ways were being found to control demand. Neither is happening, and private companies building toll roads brings howls of outrage. Why is it "politically tricky" to raise gas taxes to finance infrastructure?