Bicycling comfort at roundabouts: Effects of design and situational factors

As roundabouts replace traditional intersections, there are concerns regarding the safety of roundabouts for bicycling. Given the limitations of crash data, this study informs an understanding of bicycle safety at roundabouts in the US through an analysis of cyclists' perceptions of comfort regarding different roundabout design and operational attributes and different bicycling situations (e.g., entering, exiting, circulating) at roundabouts. In an online questionnaire, we presented 568 US adult bicyclists with renderings of a hypothetical roundabout and asked a series of questions about perceived comfort. We then used an integrated set of ordered probit regression models to analyze comfort outcomes (overall and in five situations) against roundabout attributes, while controlling for personal socio-demographics and cycling characteristics (including type of cyclist). Although most current cyclists (71%) reported some degree of comfort bicycling at roundabouts, around a third (29%) felt somewhat or very uncomfortable. Roundabouts perceived to be more comfortable for bicycling had: one (rather than two) lanes, lower traffic volumes, more bicycle facilities-especially separated bicycle lanes (a "protected roundabout")-and a larger central island. The most comfortable situations were entering and exiting the roundabout, while the least comfortable situations were riding on the sidewalk or in the crosswalk. Circulating within the roundabout was the situation rated most similar to ratings of overall comfort. "Strong and fearless" cyclists were generally more comfortable at roundabouts than "interested but concerned" cyclists, except for sidewalk riding. These results offer implications for how to make roundabouts more comfortable for people bicycling of all abilities and levels of confidence.