Has Motorization in the U. S. Peaked. Part 5: Update Through 2012.

摘要

In three of the previous four reports in this series, I examined the changes from 1984 to 2011 in the number of registered light-duty vehicles, and the corresponding changes in distance driven and fuel consumed. The units of the analyses were both the absolute numbers and the rates per person, per driver, per household, and (where appropriate) per vehicle. The main finding of those three reports is that the respective rates all reached their maxima around 2004. I argued that, because the onsets of the reductions in these rates preceded the onset of the recession (in 2008), the reductions in these rates likely reflect fundamental, noneconomic changes in society. Therefore, these maxima have a reasonable chance of being long-term peaks as well. The present report provides a brief update on these measures through 2012. The main findings of this study are as follows: (1) Despite the population growth, the absolute amount of fuel consumed by light-duty vehicles decreased by 11% during the period 2004 (the year of maximum consumption) through 2012. (2) The reductions in the rates per person, per driver, per household, and (where appropriate) per vehicle from the corresponding maxima (around 2004) to 2012 were greatest for fuel consumed (averaging about 16%), followed by distance driven (about 8%) and number of vehicles (about 6%). (The fact that the reductions were greatest for fuel consumed reflects, in part, the added contribution of the improvements in vehicle fuel economy.) (3) The 2012 rates of vehicles and distance driven were comparable to the rates during the early- to mid-1990s. The 2012 rates of fuel consumption were lower than the rates in 1984--the first year of this analysis. (4) There is no evidence in the examined data that the recent reductions in the rates were temporary. Indeed, out of the 11 rates examined, 6 showed a decrease from 2011 to 2012, 3 showed no change, and 2 showed an increase.