Pedestrian Safety Guide and Countermeasure Selection System
An example of a modern roundabout approach.
Unlike traditional signalized and stop-controlled intersections, vehicles generally flow and merge through roundabouts without having to stop; therefore roundabouts should be designed for slow speeds and geometry that facilitates motor vehicles yielding to pedestrians and bicyclists. ADA compliant pedestrian crosswalks and curb ramps should be provided at least 20 feet from the entry of the roundabout to give room for a vehicle to stop prior to the crosswalk but outside of the circulatory roadway. Channelization islands at the approaches can help slow vehicles and allow pedestrians to cross one direction of travel at a time. At-grade pedestrian cut-throughs should be provided at channelization islands with ADA compliant detectable warning strips.
Roundabouts present unique challenges for individuals with visual disabilities. Because traffic is governed by yield-control entry, as opposed to stop or signal control, pedestrians with visual disabilities must not only decide when to cross the road, but they also have to determine where and which direction to cross. Wayfinding and gap selection cues need to be adequately addressed in roundabout designs. Accessible pedestrian signals should also be considered for all crosswalks at single lane roundabouts, and are required for multilane roundabouts in accordance with the draft Public Right-of-Way Accessibility Guidelines (PROWAG).1
As stated in NCHRP 672, in order to better provide for visually-impaired pedestrians on multi-lane roundabouts, measures such as raised crossings or the pedestrian hybrid beacon should be considered. In general, multilane roundabouts are not recommended in areas with high levels of pedestrian and bicycle activity because of safety concerns of multiple threat crashes for pedestrians, especially those with visual impairments, and bicyclists. General guidance on roundabout design and control are given in several sources.1,2,3,4,5,6
Authors and Acknowledgements