Vehicle Miles Traveled

Vehicle Miles Traveled

Daily Vehicle Miles Traveled

  • Vehicle miles traveled throughout Central Texas declined between 2007 and 2009, before jumping again in some counties in 2010.
  • On-system roadways are roadways designated on the State Highway System and maintained by TxDOT.
  • Although daily vehicle miles traveled are reportedly on the decline, Austin has seen a fairly significant increase in carbon emissions from transportation since 2000 (not shown).

Daily Vehicle Miles Traveled

Travel Time Index

  • The Travel Time Index (TTI) is the ratio of peak period travel time to free flow travel time. The TTI expresses the average amount of extra time it takes to travel in the peak relative to free-flow travel.
  • Congestion in Austin is well above the average for a city of its size, with a TTI higher than Houston, Dallas and San Antonio in 2010.

Travel Time Index

Travel Time

  • Of residents that have seen a change in travel times over the past two years, twice as many think travel times have gotten longer rather than shorter.
  • The most frequent reasons for shorter travel time were changes in job (27%) or residence (17%) location, rather than improvements in traffic congestion (6%) or better roads (9%).
  • For those with longer travel times, 65% of people believe the cause is that traffic congestion has gotten worse.
Travel Time

Survey Question: Compared to 2 years ago, would you say that these days your total travel time is …

Cost of Congestion

  • The average cost per commuter in the Austin area has fallen sharply recently, coming closer in line with the average costs for other “Large” cities.
  • A University of Texas at Austin survey in 2004 revealed Austin area commuters would be willing to pay $12 to save an hour of commute time.
  • Note: TTI altered its methodology for the most recent report. The congestion estimates for all study years are recalculated every time the methodology is altered to provide a consistent data trend.

Cost of Congestion

Public Transportation Savings

  • Public transportation serves to alleviate congestion, resulting in savings to residents spending less time in traffic.
  • The Austin area lags behind the average congestion savings being realized in other “Large” cities.
  • Note: Due to methodology changes, TTI data for this measure is only available from 2007 to 2010.

Public Transportation Savings


Despite the dip in vehicle miles traveled per capita, our regional transportation system remains congested.


Central Texans have access to affordable and reliable transportation alternatives that allow them to travel efficiently throughout the region.


The effort to reduce daily vehicle miles traveled (DVMT) depends on planning and building a comprehensive multi-modal transportation system to strategically distribute work, personal and other trips. The effort also depends on individuals and families to adapt their lifestyles and travel behaviors to take best advantage of the system available to realize savings in fuel, emissions, time, and improving quality of life.


Texas Transportation Institute defines medium urban areas as over 500,000 and less than 1 million and large urban areas as over 1 million and less than 3 million. Since the 2009 CTSIP data report, Austin has been redefined as a large city based on this criteria.

The methodology used to calculate Travel Time Index and congestion costs have been developed by the Texas Transportation Institute over several years and several research projects. The congestion estimates for all study years are recalculated every time the methodology is altered to provide a consistent data trend. There were several methodology changes applicable to the most recent data, and CTSIP has included recalculated values for all study years.

Texas Dept. of Transportation

Texas Transportation Institute

CTSIP Community Survey