Bikers like to point their finger at drivers as the reason for crashes, and drivers do the same to bikers.
It turns out both are almost equally to blame.
A new analysis of 10 years of crash data has found that drivers and cyclists are almost equally at fault in the 270 reported bike-motor vehicle crashes that Minneapolis averages annually.
Biker actions contributed to the crash in 59 percent of collisions, compared to almost 64 percent for drivers, according to the study presented Tuesday to the City Council. Sometimes both were judged at fault by investigating officers.
The city's Public Works Department plans to use the data to target education campaigns at drivers and bicyclists as well as to improve bike features such as lanes, bike-triggered traffic signals and other accommodations.
"We don't want to scare people from bicycling. We want to give them information they can take in their own hands," said Shaun Murphy, the city's bike-pedestrian coordinator. The department used police reports to analyze the crashes.
Crashes often occur because drivers don't see or yield to bikes, the study found, or when bikers behave unpredictably by ignoring red lights or riding against traffic.
Although investigators often were unable to determine a clear cause for accidents, the pattern differed by mode of travel. For example, drivers failed to yield in 32 percent of cases, often when making a right or left turn, compared with 13 percent for bikers. But bikers more often ignored signs or signals.
'It's all people'
David Meyer, who rides and works at the Hub Bike Co-op, said the shared fault makes sense to him. "It's all people -- just taking different modes of transportation," he said.
Not surprisingly, the top intersections for bike-motor vehicle crashes are those with the greatest traffic. The complex junction of Cedar, Franklin and Minnehaha Avenues led the list with 20 crashes reported over 10 years, followed by two downtown spots on Hennepin Avenue.
Some of the top crash sites have bike lanes while others don't, and their configuration sometimes changed during the study period. Several arterial streets with the highest crash rates, such as 26th and 28th Streets or Broadway, lack bike lanes, while Lowry Avenue got them only partially and late in the study period.
Nick Mason, chairman of the panel that advises the city on bike matters, called the study "definitely the most thorough analysis we've seen of crashes."
"It's so great to know that our crashes are not all random ... and there are things we can do to prevent crashes," he said.
The report urges that the city continue such practices as striping bike markings through congested intersections to guide cyclists or using dashed lines to signal to drivers when they can cross a bike lane for a turn.
It also urged continuing training for truck and bus drivers on bike awareness, as well as wide use of public service videos posted online for other drivers and bikers about road safety. It also urged that bikers and motorists receive even-handed enforcement.
The analysis of data from 2000 to 2010 covered only crashes for which an accident report was filed. It found that bikers sustained some injury in 87 percent of those crashes, and 10 died over the 10-year period, with two more in 2011.
Beware the p.m. rush hour
Collisions were most likely to happen during the afternoon rush hour. Eighty-one percent of crashes occurred within 50 feet of an intersection. One of five crashes were classified as hit-and-run, with the driver the fleeing party 93 percent of the time.
One limit to the data is that it includes only reported crashes, and other studies using hospital visits estimate that between one-third and two-thirds of crashes go unreported to police.
The study found evidence reinforcing a previously reported pattern of a lower crash rate as the city's bike commuting population rose sharply in the past decade, which has been attributed to drivers being more aware of bikers as they turn out in greater numbers.
The bike crash rate is about one-third its 1997 peak, due to that awareness and more designated lanes for cyclists. The crash rate is lower on streets with high volumes of bikers than those with fewer bikers, the study found.
One example is Hennepin Avenue. Despite some of its intersections ranking high in crashes, the downtown stretch of that street ranked lower in the rate of crashes. The analysis also found that streets with bike lanes, such as downtown Hennepin or University Avenue SE., tend to have lower crash rates than streets like Lowry Avenue or 28th Street with only partial or no such markings.
"Cyclists are much more likely to ride in a predictable manner if they have a place to ride," said Ethan Fawley, president of the Minneapolis Bicycle Coalition.
Fawley said the findings lend support for the coalition's goal of protected bikes lanes, those separated from traffic lanes by curbs, parked cars or posts and cables. They give more assurance to those hesitant to bike on high-traffic routes such as Portland and Park Avenues, he said.
The report also found that a substantial portion of potential bike commuters won't ride unless they feel protected doing so.
Steve Brandt • 612-673-4438 Twitter: @brandtstrib