The number of vehicle miles traveled in the U.S. increased by 4.4 percent in 2015, according to numbers released by FHWA last week, setting a new record of 3.1 trillion miles. After testing several variables and model variations, we developed a model of VMT per capita based on GDP per capita and average annual gas prices. This model tracks actual VMT per capita very closely, including the recent increase, but only after we adjust for new trends observed over the past 20 years.