Source: Texas Transport Institute.
Factors Contributing to the Growth of Driving in the United States
A set of factors have converged to explain the growth of the usage of the automobile in the United States, as measured in vehicle-miles:
  • Demographic growth is a straightforward factor as the more people the more potential drivers and thus of vehicles.
  • The increase in trip length as well as the number of trips often relates the changes in the urban spatial structure. Particularly, suburbanization involves longer trips.
  • A decrease in vehicle occupancy is commonly linked with limited opportunities for car pooling and trip chaining.
  • In view of limited alternatives or the low convenience of public transit, many will switch to driving. Switching to driving is also the outcome of rising standards of living where a larger segment of the population reach an income level where an automobile becomes affordable.
Similar factors apply in other countries, but proportions would be different. For instance, in developing economies the increase in population and income would be among the most significant factors explaining the growth in vehicle-miles.