A new study is out today that shows that bicycle fatalities have accelerated by an alarming rate. According to the Governors Highway Safety Association (GHSA), 621 cyclists were killed in vehicular crashes nationwide in 2010. That number rose to 680 in 2011, and to 722 in 2012, for a total increase of 16 percent. During the same period, motor vehicle deaths grew by 1 percent.

This is troubling news to safety advocates, for until 2010, cyclists fatalities had been dropping steadily since 1975. Unsurprisingly, the spike correlates with the huge 62 percent surge in bike commuting since 2000, particularly among urban cyclists.

“This is a very discouraging to see,” Seattle Bike Blog author Tom Fucoloro told Seattle Weekly this morning. “And it is because the car culture hasn’t changed yet, at least in the heartland. Things are better, though, in Seattle.”

In Seattle, there have been at least a dozen fatal collisions since 2007. Some of the higher-profile crashes include a car that killed Robert Townsend in the University District in 2011, and hit-and-run SUV that took the life of Mike Wang that same summer on Dexter Avenue North. More recently, 31-year-old Seattle attorney Sher Kung was killed in late August on the city’s dangerous and heavily traversed Second Avenue.

Collisions have slowly inched up in Seattle as cycling becomes more popular and streets more congested. There were 352 collisions in 2011 and 407 in 2012, the most recent years the city has data for, the vast majority of which resulted in injuries.

Some other findings in the GHSA report:

–Fatal cycling crashes in cities represented 69 percent of all fatalities in 2012, compared to 50 percent in 1975.

–About 88 percent of the victims were male.

–Nearly two-thirds of all cyclists killed were not wearing helmets.

–Almost one-third – 28 percent – of cyclists killed and who were over 16 exceeded the legal limit (.08 percent) in their blood alcohol concentration.