2015 marks largest increase in traffic deaths in 50 years
WASHINGTON -- Preliminary estimates show that the number of traffic deaths rose by 8 percent in 2015 -- the largest year-to-year percentage increase in a half-century.
The National Safety Council says about 38,300 people were killed on U.S. roads last year, and 4.4 million people were seriously injured. That would make 2015 the deadliest driving year since 2008.
The council says a stronger economy and lower unemployment rates are probably among the key factors - along with lower gas prices. With driving more affordable, more people are on the road.
"Lower gas prices, more people are driving longer distances or more miles, the more people on the road, the more people driving long distances, the greater the risk," AAA's Tom Calcagni previously told CBS News.
Another possible reason traffic deaths are up: passengers not wearing their seat belts. Back seat passengers are a particular concern as they are less likely to buckle up, and 22 states do not require it. But back seat riders are still very much at risk in a crash, CBS News reported in November.
Dr. Jim Hedlund studied back seat passenger behavior. "It takes a second, you don't have to think about, it doesn't cost you anything," Hedlund said of wearing a seat belt. "It is cheap, easy, and it may save your life."
The Transportation Department estimates there was a 3.5 percent increase in the number of miles driven by Americans in 2015.
The council is a nonprofit organization created by Congress to promote safety.