Contextual Guidance at Intersections for Protected Bicycle Lanes

Improved bicycle infrastructure has become increasingly common in the United States as cities seek to attract new riders, including the demographics of people who do not feel comfortable riding with motor vehicle traffic. A key tool is separated or protected bicycle lanes, and intersections are critical links in a low-stress network. This report presents an analysis of the perceived level of comfort of current and potential bicyclists from 277 survey respondents who rated 26 first-person video clips of a bicyclist riding through mixing zones, lateral shifts, bend-in, bend-out and protected intersection designs. A total of 7,166 ratings were obtained from surveys conducted at four locations in Oregon, Minnesota and Maryland, including urban and suburban locations. Survey respondents were categorized into three groups based on their response to attitudes and bicycling behavior by a cluster analysis. Descriptive analysis and regression modeling results find that designs that minimize interactions with motorists, such as fully separated signal phases and protected intersections, are rated as most comfortable (72% of respondents rated them as very comfortable or somewhat comfortable). Mean comfort drops off significantly for other designs and interactions with turning vehicles result in lower comfort ratings, though there are differences for each design. Importantly, as the exposure distance, measured as the distance a person on a bicycle is exposed to traffic, increases the comfort decreases. For each of the designs, the expected frequency with which cyclists would encounter turning motorists based on expected bicycle volume and expected right-turn volume was established using microsimulation. These estimated interactions were combined with the survey results to produce guidance for design selection based on comfort