The main funding source for transportation infrastructure is the Highway Users Tax Fund (HUTF), which is funded by a state gas tax and license/registration fees. Though the price of gas has steadily increased, the gas tax rate has remained unchanged since 1991, and now accounts for a mere 22 cents per gallon of gas.
After 11 percent is automatically allocated to help fund Colorado State Patrol and the Department of Motor Vehicles, the remainder is split with 60 percent going to CDOT and 40 percent going to cities and counties. Annually, CDOT receives $400 million from the HUTF, but spends over $684 million just to maintain the current system, accounting for 63 percent of their $1.1 billion budget.