Lane Transgressions at Roundabouts

Roundabouts are quite effective as junction control measures; reducing crashes by eliminating certain conflict points and managing capacity by virtue of its self-regulating ability. Amongst other forms of circulatory carriageway markings, spiral markings have been acknowledged as a way of reducing a driver's decision-making responsibilities and leading drivers to their choice exit lanes hence improved safety. Considering the debate on roundabouts, a question comes to mind; "what proportion of drivers contravene the principles of lane discipline which several authors claim to be the highlight of spiral markings?" It was on this premise that this research was borne with specific objectives of observing the lane discipline at Sheriffhall roundabout, Midlothian, Edinburgh, United Kingdom. This was achieved by installation of video cameras at strategic locations around the circulatory carriageway of the roundabout, with an observational study (survey), analysis of same considering class of vehicles, traffic and light conditions being carried out. The results revealed very interesting trend.