By Maggie Fox, Health and Science Editor
WASHINGTON (Reuters) - Air bags and the economic recession have contributed to the biggest drop in road deaths in the United States since World War II, U.S. researchers said on Tuesday.
Changes in driving patterns and safety features both contributed to a 22 percent decline in road deaths between 2005 and 2009, Michael Sivak and Brandon Schoettle of the University of Michigan said in a report that studied federal data looking for the causes associated with fatal crashes.
"From 2005 to 2009, U.S. road fatalities dropped by 22 percent (from 43,510 to 33,963). A reduction of such magnitude over such a short time has not occurred since road safety statistics were first kept (starting in 1913), except for the reductions during World War II," they wrote in the journal Traffic Injury Prevention.
"We were amazed by the magnitude of this," Sivak said in a telephone interview.
Separately, the U.S. Centers for Disease Control and Prevention reported that 85 percent of American drivers say they use seat belts all the time, while 1 in 7 do not.
Traffic deaths in 2009 were the lowest since 1954, the U.S. Department of Transportation said in March.
"The two general factors that we are putting our money on are technological advances, primarily air bags, and the economic downturn," Sivak said.
He and Schoettle analyzed traffic patterns and found, for instance, an overall 4 percent drop in traffic, with notable decreases during rush hour and less traffic on high-speed interstate highways. They also found fewer crashes involving trucks, along with data that less freight is being shipped.
"This supports the notion that people are cutting down on travel and staying closer to home. Traffic on local streets has increased," Sivak said.
Federal statistics include a code for factors involved in fatal crashes and they point to a big increase in inattentive driving.
"U.S. data combine talking, eating and using cell phones in the same group. We have seen an increase of 42 percent in fatal crashes in which the coder labeled inattention as a factor," Sivak said.
In October researchers at the University of North Texas Health Science Center calculated that drivers using cell phones killed 16,000 people from 2001 to 2007.
In 2009 the U.S. government blamed distracted driving for 16 percent of road deaths, or 5,800 deaths.
Sivak said it was difficult to say how much any one factor contributed to overall deaths, but there are clues pointing to the decline in fatalities.
"We have found there has been an increase in the deployment of air bags during crashes, especially side air bags," he said. "We have been driving less and we are driving differently."
(Reporting by Maggie Fox, Editing by Anthony Boadle)