Link to the Iowa DOT Homepage Link to the State of Iowa Homepage


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.


Definitions for Vehicle Miles of Travel (VMT)

30-Year Historical VMT By System

1991-2000 Historical VMT By County & System

VMT by County and System VMT by Classification Monthly VMT
2011 2011 2011
2010 2010 2010
2009 2009 2009
2008 2008 2008
2007 2007 2007
2006 2006 2006
2005 2005 2005
2004 2004 2004
2003 2003 2003
2002 2002 2002

Transportation Data Logo
This Iowa DOT page is maintained by
Mark Hansen mark.hansen@dot.iowa.gov
Your questions and comments are welcome.
©2011, Iowa Department of Transportation
Last updated:
Thursday, 28-June-12 08:52:40-MH