Risk of traffic death is falling

The risk of dying in a traffic crash has dropped nearly 18 percent since 2005, according to preliminary statistics released by the Transportation Department, although experts say they are not sure why. The recession and gas prices have reduced the number of miles traveled, and perhaps cutting average speed, at least for part of the period.  Government officials and other experts also cited safer highways, higher seat belt use, added safety features in newer vehicles, and teen license restrictions.