Source: US Department of Transportation, Federal Highway Administration.
The growth of vehicle miles traveled (VMT) within the United States is punctuated by sharp periods of decline corresponding to recessions. The drops attributed to the first (1973-74) and second (1979-80) oil shocks were particularly pronounced. However, growth rates resumed immediately afterward to their previous levels. The overall growth trend has steadily declined, which is common in all diffusion processes as the activity moves towards maturity. While VMT growth rates in the 1980s were in the range of 4%, they declined to 2.5% in the 1990s and around 1% in the 2000s. Since 2006, growth stopped and then reversed sharply, which could indicate that a peak level of car mobility may have been achieved, at least in developed countries such as the United States.
Several factors could explain the apparent peak in the total annual vehicle distance traveled. One has been steadily increasing energy prices, particularly in the first half of 2008 when a third oil shock was unfolding. Yet, as oil prices substantially declined afterward, there was no resumption of VMT growth; they remained flat. Another factor was the 2009-10 recession, where lower levels of economic activity negatively impacted ridership. The aging of the population may also be a factor at play, as well as the slow down in suburbanization. Low or negative growth levels in mobility are also related to lower consumption levels, particularly in automobiles and related goods and services, and a new generation less inclined to use the automobile. The current context is indicative of limited additional growth prospects in mobility, at least mobility related to the automobile.