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Center for Advancing Research in Transportation Emissions, Energy, and Health (CARTEEH)

A USDOT University Transportation Center

Change in VMT Before and After Intervention  

Vehicle miles traveled (VMT) before and after intervention is a measurement often used in transportation planning for many purposes. It compares the number of trips made by all vehicles in a specific area before and after the metric’s adoption, usually over the course of one year. The total miles driven by all the vehicles are used to compute it. Because it indicates overall travel, how travel varies over time, and variations in travel across regions and states, VMT is a crucial indicator in transportation planning.1

This indicator helps determine the effectiveness of the following objectives

  • Less Contamination
  • Less Emissions
  • Less Traffic Noise
  • Connectivity and Inclusion
  • Healthy Destinations
  • Less Traffic Violence
  • Active Transportation
  • Green Space

Data Collection

The official Streetlight website is one example that contains data about the VMT per capita. Every day, Streetlight calculates the total number of miles driven by vehicles (VMT) throughout all 50 states in the United States.2

Examples

Personal Transportation Factsheet by the University of Michigan

In a new study, researchers at the University of Michigan looked at data on changes in vehicle miles traveled (VMT) from 2005 to 2015 for large cities across the United States (University of Michigan, 2021). They found that the average VMT per person declined by about 5 per cent during that period. The researchers also found that the decline in VMT was not uniform across all cities. Some cities, such as San Francisco and Seattle, saw much larger declines than others. The study’s authors say that the findings could have implications for transportation planning and policy. They say that if the trend of declining VMT continues, it could lead to less congestion and fewer emissions. The study was published in the journal Nature Sustainability.

https://css.umich.edu/publications/factsheets/mobility/personal-transportation-factsheet

1. Policy research CENTER methodologies used to estimate and forecast vehicle Miles traveled (VMT) [Internet]. Tamu.edu. [cited 2022 Jul 13]. Available from: https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-2016-pdf
2. StreetLight Data, Inc. Download VMT data for all U.S. counties [Internet]. Streetlightdata.com. [cited 2022 Jul 29]. Available from: https://learn.streetlightdata.com/vmt-data-counties