The main contribution of this study is an examination of recent trends in distances  driven by light-duty vehicles (cars, pickup trucks, SUVs, and vans) in the U.S. fleet.  This is in  contrast to several other recent studies that analyzed distances driven by all vehicles (including  medium and heavy trucks, buses, and motorcycles).  The period examined was from 1984  through 2011.  This is a follow-up study to Sivak (2013), in which I analyzed the recent trends  in the number of registered light-duty vehicles.

Although the report also presents trends in the absolute distances driven, of primary  interest were the distances driven per person, per licensed driver, per household, and per  registered vehicle.  All of these rates reached their maxima in 2004—four years prior to the  beginning of the current economic downturn—and decreased by 5% to 9% by 2011.  These  reductions likely reflect, in part, noneconomic changes in society that influence the need for  vehicles (e.g., increased telecommuting, increased use of public transportation, increased  urbanization of the population, and changes in the age composition of drivers).  Because the  onset of the reductions in the driving rates was not the result of short-term, economic changes,  the 2004 maxima in the distance-driven rates have a reasonable chance of being long-term  peaks as well.  An exception is the rate per registered vehicle.  Should the numbers of vehicles  per person, per driver, and per household continue to fall (Sivak, 2013), it is possible that the  distance driven per vehicle would eventually start to increase and thus this rate has a better  chance in the future of surpassing the 2004 maximum.

The combined evidence from this and the previous study (Sivak, 2013) indicates that—  per person, per driver, and per household—we now have fewer light-duty vehicles and we  drive each of them less than a decade ago.  The best estimates of the current annual distance-  driven rates by light-duty vehicles are as follows: 8,500 miles per person, 12,500 miles per  licensed driver, 22,100 miles per household, and 11,300 miles per registered vehicle.