A century ago, Oregon adopted the first state gas tax, later dedicating the proceeds to building out the state's road network. Within a decade, every other state in the country followed.
Since then, many Americans have been under the impression that the money they pay in gas taxes, registration, and other vehicle-related fees is enough to cover the costs of building and maintaining the millions of miles of roads they use.
Today, however, revenue from highway users covers only a little more than half the cost of building and maintaining the nation's roads. Most of the rest of the money comes from general tax revenue that you and I pay regardless of how much we drive or whether we even own a car.