Introduction
The total number of miles driven by all vehicles is referred to as Vehicle Miles Traveled, or VMT. The total traffic volume in a region is an important factor to consider in deciding when, where and whether new roads, or additional lanes on existing roads, need to be built. Moreover, since gasoline taxes constitute the principal source of funding for transportation projects, changes in VMT can significantly affect transportation financing.
For these reasons, it is important for transportation planners to be able to forecast VMT trends. In the past few decades, there has been a dramatic increase in VMT, both in the US and in the St. Louis area. However, recent evidence indicates that VMT is no longer growing, or at least that it is no longer growing as rapidly. To be sure, there are local “hot spots” where traffic volume does continue to increase. However, these high volume areas are not representative of the entire
region. Social and demographic factors that affect VMT include the age of the population, household size, labor force participation and car ownership. This report summarizes recent trends in VMT growth and in the factors that affect VMT growth.

Read more >>>>