Lessons from the Green Lanes: Evaluating Protected Bike Lanes in the U.S.

摘要

This report presents finding from research evaluating U.S. protected bicycle lanes (cycle tracks) in terms of their use, perception, benefits, and impacts. This research examines protected bicycle lanes in five cities: Austin, TX; Chicago, IL; Portland, OR; San Francisco, CA; and Washington, D.C., using video, surveys of intercepted bicyclists and nearby residents, and count data. A total of 168 hours were analyzed in this report where 16,393 bicyclists and 19,724 turning and merging vehicles were observed. These data were analyzed to assess actual behavior of bicyclists and motor vehicle drivers to determine how well each user type understands the design of the facility and to identify potential conflicts between bicyclists, motor vehicles and pedestrians. City count data from before and after installation, along with counts from video observation, were used to analyze change in ridership. A resident survey (n=2,283 or 23% of those who received the survey in the mail) provided the perspective of people who live, drive, and walk near the new lanes, as well as residents who bike on the new lanes. A bicyclist intercept survey (n= 1,111; or 33% of those invited to participate) focused more on people’s experiences riding in the protected lanes. A measured increase was observed in ridership on all facilities after the installation of the protected cycling facilities, ranging from +21% to +171%. Survey data indicates that 10% of current riders switched from other modes, and 24% shifted from other bicycle routes. Over a quarter of riders indicated they are riding more in general because of the protected bike lanes. A large majority of drivers and bicyclists stated that they understood the intent of the intersection designs and were observed to use them as intended, though specific designs perform better than others on certain tasks. No collisions or near-collisions were observed over 144 hours of video review for safety at intersections, including 12,900 bicyclists. Residents and bicyclists indicated that any type of buffer shows a considerable increase in self-reported comfort levels over a striped bike lane, though designs with more physical separation had the highest scores. Buffers with vertical physical objects (those that would be considered protected lanes - e.g. with flexposts, planters, curbs, or parked cars) all resulted in considerably higher comfort levels than buffers created only with paint. Flexpost buffers got very high ratings even though they provide little actual physical protection from vehicle intrusions— cyclists perceive them as an effective means of positive separation. Support for the protected lanes among residents was generally strong with 75% saying that they would support building more protected bike lanes at other locations, and 91% of surveyed residents agreed with the statement, u22I support separating bikes from cars.u22 This agreement was high among primary users of all modes (driving, walking, transit, and bicycling), though motorists expressed concerns about the impacts of protected lanes on congestion and parking. Most residents also agreed with the statement u22I would be more likely to ride a bicycle if motor vehicles and bicycles were physically separated by a barrier,u22 with u22Interested but Concernedu22 residents expressing the highest level of agreement at 85%. Nearly three times as many residents felt that the protected bike lanes had led to an increase in the desirability of living in their neighborhood, as opposed to a decrease in desirability (43% vs 14%).