Vehicle miles traveled (VMT) was seven times higher in 2017 than in 1950. The number of vehicles in operation was more than six times higher in that same period, while the resident population doubled. Growth of VMT and vehicles slowed from 2008 to 2011 but continued the upward trend thereafter. Because the number of licensed drivers grew more slowly than VMT did, the average miles per driver increased each year. Similarly, with the number of households growing more slowly than the number of vehicles in operation, vehicles per household also increased each year.