Citation

Thompson H. ITE J. 2009; 79(8): 46-49.

Copyright

(Copyright © 2009, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

Although roundabouts have an excellent safety records for intersection control, problems can arise. This paper highlights examples from Britain that address some of these safety problems. Some of these safety problems are due to the constraints of the location. Many problems can be avoided by ensuring that a roundabout is the best solution for that location and by careful design and construction. Problems may result form lack of forward visibility, see-through effects (such as when a roundabout is located in a dip on a straight road with the exit leg visible but the roundabout itself hidden), or unexpected queuing. Potential solutions include advance signage, high-friction surfacing, transverse yellow bar markings, street lighting, and forgiving roadsides. Sigh screens can be effective in slowing drivers down until they have a clear sightline, forcing them to enter the roundabout at a slower speed. Under some circumstances, it might be necessary to install traffic signals in the roundabout, especially if the circulating traffic flow is so heavy that gaps are few. Although these examples are pulled from the British experience with roundabouts, they can be adapted for use in roundabouts in other countries.