A new study has found that buffered bike lanes are better than conventional bike lanes, at least when it comes to encouraging bicyclists to ride outside the door zone. The study draws its conclusion, in part, based on a test done with bike lanes in Chicago by a Chicago Department of Transportation consultant.
The study, recently published by the Transportation Research Board, concludes that wider (but un-buffered) bike lanes aren’t necessarily better than narrower lanes in encouraging bicyclists to ride outside the door zone. They wrote that if there’s enough space to make a wider bike lane, that extra space should be used to install a “narrower bicycle lane with a parking-side buffer,” which “provides distinct advantages over a wider bike lane with no buffer.” In one test on a Chicago street, few bicyclists rode outside the door zone when given conventional lanes, but 40 percent rode outside the door zone when the lane was re-striped with a two-foot buffer.
That’s because the door zone is four feet wide, and riding in the center of a six-foot-wide bike lane still doesn’t give a cyclist enough clearance. The Chicago Bike Map itself recommends riding four feet away from parked cars, well outside the center line of even a six-foot-wide lane.
Chicago Department of Transportation bikeways engineer Nathan Roseberry contributed to the study, which specifically demonstrated through on-road tests that a six-foot wide bike lane offers no advantage over one that’s five feet wide, or even four feet wide. That’s because bicyclists still ride in the center of the lane — within the area that a typical car door will cover if it swings open and possibly strikes a passing rider. Dooring crashes are common in urban areas like Chicago: In 2012, the last year for which data is available, 18 percent of reported bike crashes were doorings.
Chicago has several six-foot-wide bike lanes, including those on Elston from North Avenue into the far northwest side, Division Street through Wicker Park, and Milwaukee between Division and Elston. The on-road test, using temporary bike lane stripes, took place on Division Street near California, and on Clark Street near Schiller. Both streets did not have bike lanes before, and then bike lanes of varying widths were installed, culminating in the buffered lanes that exist at those locations today. Read more…