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Cyclist Safety Improves with Bike Lanes

Streets Without Bike Lanes are Less Safe, Study Finds

Mar 13, 2012

BALTIMORE, MD–– In one of the first U.S. studies of its kind, researchers at the Johns Hopkins Center for a Livable Future at the Bloomberg School of Public Health have found that bike lanes in Baltimore improve cyclist safety, in a paper published in the Journal Accident Analysis and Prevention on March 27, 2012. The study looked at drivers’ behavior around cyclists on roads with and without bike lanes, and the good news is that drivers pass significantly wider when cyclists are in bike lanes.

The bad news is that on roads without bike lanes, drivers had trouble sharing the road with cyclists, which often violated a state law aimed at making cycling safer. In 2010, Maryland passed what is known as the “3-foot law,” which requires that drivers must pass cyclists by three feet or more. The study authors found that one in six motor vehicle passes in Baltimore, or about 17 percent, violated the 3-foot law.


Researcher David Love, PhD, a project director at the Center for a Livable Future (CLF), says that, “As cyclists, we knew the 3-foot law was not being followed, and we wanted to quantify the problem. Now, for the first time, we have baseline data to inform future transportation and planning efforts.”

Violations to the 3-foot law were virtually non-existent on streets with bike lanes.  Love notes, “we need to find ways to separate car traffic from bike traffic, and bike lanes are one way to do that.”

The study was conducted by a team of six Johns Hopkins University faculty, staff and students, including CLF director Robert Lawrence, PhD, who routinely commute to work or school by bicycle. The authors attached video cameras to their bicycles, recording commutes in the Fall of 2011. By translating video footage into data, the study authors documented experiences that others in Baltimore have reported only anecdotally.

Researcher Jared Margulies, a program officer at CLF, says, “many cyclists feel safer in bike lanes, and our data indicates that drivers do give cyclists more room when bike lanes are present.”

The study was sponsored in part by Bike Maryland, a state-level bike advocacy group. Carol Silldorff, executive director of Bike Maryland, says “our organization had a hand in the passage of Maryland’s 3-foot rule, so we are glad to support research to assess motorist compliance with the law in Maryland’s largest city ” 

The study has not looked at intersections, which is the predominant location for bicycle-vehicle collisions.  More research is needed on that topic. “We in Baltimore are on a learning curve,” says Love, who cited Washington, D.C., Portland, Oregon, and New York City as implementers of innovative approaches to engineering safer spaces for cyclists.

About Bike Maryland

Bike Maryland is the nonprofit organization that has been instrumental in improving bicycling conditions and protecting the rights of bicyclists across Maryland. We are the only organization actively promoting pro-bike legislation on the state level in Maryland. We improve conditions on the county and city level too. Our mission is to promote bicycling, increase safety, improve conditions, and provide a voice for bicyclists in Maryland.