Rear view of triathletes cycling on street
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By Noah Rayman
October 27, 2014

The number of bicyclists killed in motor-vehicle crashes jumped up 16% between 2010 and 2012, after many years of decline.

A study released Monday by the Governors Highway Safety Association suggests that recent growth in the popularity of biking has contributed to the rising death toll, though the findings do not offer conclusive data.

“To the extent encouragement of bicycling is successful, exposure and fatalities are likely to continue to increase,” the study says.

In 2012, the most recent year in which figures are provided, 722 bikers were killed in motor-vehicle crashes, up from 621 in 2010. The figure is still down from 1975, when the data was first compiled and 1,003 people were killed in motor-vehicle crashes.

The majority of bikers killed in motor-vehicle crashes were adults over the age of 20, a dramatic shift from 1975 when the majority of bikers killed in motor-vehicle crashes were younger than 20, and adults comprised only 21%.

The study also found that the lack of helmets was a “major contributing factor” in fatalities. More than two-thirds of fatally injured bikers were not wearing helmets, though it’s not clear what portion of riders generally wear helmets.

One figure has remained relatively constant since at least 1982: roughly a quarter of bikers over age 16 who were killed in 2012 had been drinking.

“Despite the association of biking with healthy lifestyles and environmental benefits, a surprisingly large number of fatally injured bicyclists have blood alcohol concentrations of 0.08% or higher,” the study said.

Write to Noah Rayman at noah.rayman@time.com.

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