Shared lanes better for bike safety on narrow streets

March 5, 2010
By

In their letter to the editor (JP Gazette, Feb. 19) “Bike lanes encourage safe bicycling,” Sherry Eskin and Lauren Ockene say that bike lanes on Centre Street will improve bicycle safety. The only direct evidence they give is a study conducted by the City of Cambridge shortly after Dana Laird was killed while riding in a Central Square bike lane. Her handlebar hit a suddenly opened car door, and she was thrown into the path of an overtaking bus.

The study found that a bike lane added to Hampshire Street moved bicyclists on average 2 inches farther away from parked cars. However, after the bike lane was marked, 85 to 90 percent of bicyclists still positioned their wheels less than 11 feet from the curb.

The outer extent of an open door on a legally parked car can be as much as 10 feet from the curb. Bicycle handlebars are generally 2 feet wide. So a bicyclist whose wheel is 11 feet from the curb has barely enough room to consistently clear the door zone. The left edge of the proposed bike lane is 12 feet from the curb, meaning that no more than the left-most 1 foot of the nominally 5-foot bike lane is safe for use. But bicyclists are expected to be in the middle of the lane, and that is where unwary bicyclists ride (until they get doored).

I suggest that shared lane symbols be used instead for Centre and South streets to show that bicyclists are intended to be safely away from the door zone. By federal rules, these bicycle symbols must be centered at least 11 feet from the curb where there is on-street parking. Shared lane markings are already on the ground in Forest Hills, Roslindale and several other places in Boston.

Perhaps because there is no evidence that bike lanes by themselves improve bicyclist safety, Sherry and Lauren resort to the indirect argument that safety will come from motorist awareness, which will come from more bicycling, which will come from more bike lanes—even if they are of the kind that encourage dangerous behavior such as riding in the door zone. Surely there are other ways to improve motorist awareness besides encouraging new cyclists to ride in the door zone.

In fact, we know that bicyclists can be safer by learning and following a few basics: ride on the right half of the road, not the sidewalk; use lights at night; look back before moving across the road; use the correct lane at intersections; yield to other traffic when required by law; don’t pass moving vehicles on the right; and stay away from road hazards.

I support bicycle lanes where they do not discourage safe bicycling, including pocket bike lanes next to turn-only lanes.

Paul Schimek
Jamaica Plain

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