Michael Sivak of the University of Michigan's Transportation Research Institute said road fatalities dropped 26 percent from 2005 to 2011 but were up 8 percent over the first seven months of this year.
"After a recent peak of 43,500 fatalities in 2005, fatalities dropped to 32,300 in 2011," Sivak said in a statement. "The last time road fatalities were lower was in 1949 when, relative to 2011, we had only about 17 percent of the vehicles on the road and drove only about 14 percent of the miles. That is a remarkable reduction in fatalities."
Sivak said vehicle manufacturers, federal regulators, driver-licensing agencies and public-interest groups have taken credit for the drop -- and all contributed -- but there is another factor: the economy.
"As a consequence of the economic downturn, we have reduced the amount of driving, but not enough to fully account for the magnitude of the fatality drop," Sivek said. "However, we have also changed our patterns of driving. For example, we have been driving slower, partly to improve vehicle fuel economy. Further, we have reduced higher-risk exposure, such as leisure driving in rural areas, more so than lower-risk exposure, such as commuter driving in urban areas."