The vehicle miles of travel (VMT) summary information is calculated from traffic counts taken on
state, county, and city roadways from both manual counts as well as automatic traffic recorders. The resulting traffic volume data is combined with the
roadway length from the Geographic Information Management System and summarized in several formats. The information is used to meet Federal Highway
Administration reporting requirements as part of the Highway Performance Monitoring System and provides a measure of highway vehicle travel usage
over a geographic area, such as a county, state, or highway system. These estimates also provide a basis in calculating crash and fatality
rates for measuring highway safety.