ACCOMMODATING SMALL AND LARGE USERS AT ROUNDABOUTS

Roundabout designs should be balanced to accommodate the mix of pedestrians, cyclists, and motorized vehicles (such as cars, buses, trucks, oversize loads, etc.) expected to use the intersection. Each user class has different characteristics and time/space requirements, and optimizing the design for one user class often reduces the suitability for other users. The task of the designer is to find the design trade-offs that optimize safety and operations for the entire mix of users of the intersection under consideration. This paper highlights a variety of issues related to “small” users at roundabouts, principally pedestrians and cyclists, and “large” users at roundabouts, namely trucks. Issues with pedestrians and cyclists include accommodating pedestrian crossing movements, pedestrian safety, pedestrian education (including an innovative program in the Regional Municipality of Waterloo, Ontario), visually-impaired pedestrians, accommodating cyclists, and cyclist safety. Issues with trucks at roundabouts mainly involve accommodating trucks within the available geometry, whether to employ circulatory road striping (and the fact that trucks commonly encroach on adjacent lanes in multi-lane roundabouts), and lessening the potential for truck overturning at roundabouts.