M Street bike lane markings Most Bike to Work Day cyclists won’t be able to ride in protected lanes. (Robert Thomson – The Washington Post)

Bike riding, particularly among urban commuters, is up, and the trend has led to a 16 percent increase in cyclist fatalities nationwide, according to a new study set to be released Monday.

In 2010, 621 cyclists were killed in vehicular crashes nationwide. That number grew to 680 in 2011 and to 722 in 2012, for a total increase of 16 percent, according to the study by the Governors Highway Safety Association. Over the same period, other motor vehicle deaths grew by 1 percent.

The trend has troubled safety advocates because, until 2010, the number of cyclist fatalities annually had been dropping steadily since 1975. The recent increase correlates with a 62 percent surge in bicycle commuting since 2000. Governments have promoted cycling as a way to reduce traffic, curb vehicle emissions and improve public health.

Analysts also have seen big changes in who’s getting killed on bikes and where, the study said. Fatal cycling crashes in cities now account for 69 percent of all fatalities in 2012 compared to 50 percent in 1975.

Bicycling being used more for commuting also is affecting the age of accident victims. In 2012, adults 20 and over comprised 84 percent of bicycle fatalities. That compares to adults making up only 21 percent in 1975.

Cycling fatalities still occur mostly among men — 88 percent of victims in 2012 were male –and two-thirds of all cyclists killed weren’t wearing helmets. Nearly one-third — 28 percent — of cyclists killed who were age 16 or older had a blood alcohol concentration of .08 percent or higher.

Safety advocates also are concerned that the percentage of cyclists killed with high alcohol levels has remained relatively constant since the early 1980s, even as the percentage of alcohol-impaired drivers in fatal motor vehicle crashes has had a “sharp drop,” the study said.

States are working to increase cyclists’ safety by promoting helmet use, enforcing traffic laws and designing streets better for cyclists and pedestrians, as well as vehicles, the association said.