Vehicle miles of travel (VMT)

Vehicle miles of travel (VMT) is a measure of all the miles driven within a specified area and timeframe. Most traffic counts are reported in terms of annual average daily traffic (AADT) and represent an estimate of the number of vehicles traveling along a given point on a highway on an average day in the year. VMT estimates, while based on AADT estimates, include the distance traveled element and thus provide a measure of highway vehicle travel usage over a geographic area, such as a county, state, or highway system. VMT captures aggregate trends on a broad range of corridors.

Vehicle miles of travel by highway system

Vehicle miles of travel by county

Road mileage and annual VMT in Wisconsin

To see how VMT is trending to date, go to the Federal Highway Administration's (FHWA's) Travel Monitoring website.

Data prior to 2009 is available upon request.


Miao Zhang
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How is VMT estimated?

VMT summarizes travel from the previous year. Estimation methods can be found in Chapter 9, Section 40, Subject 2, of the WisDOT Transportation Planning Manual.

How is VMT used?

  • VMT is a planning tool to help identify whether driving has increased or decreased.
  • VMT is used to assist with future travel trend analysis by planners, budget analysts and engineers.