This article presents the main results of accidents studied at 522 roundabouts in Western France. Two sets of results are analyzed: (a) all injury accidents on any roundabout either since its construction, or since 1984 if constructed earlier than this date; and (b) injury accidents in 1988. Most (80%) of the roundabouts studied are in urban or semi urban areas. The remaining 20% are either in urban areas or on industrial or commercial estates. Most are small, with an average radius of less than 15m. Seventy five per cent have 3 or 4 branches and about 20% have 5 branches or more. The average daily traffic (AADT) per roundabout is about 12500 vehicles per day. In 1988, there were 78 accidents, 5 of which were fatal and 26 of which involved serious injury. Details are provided of distribution of accidents according to roundabout location (open countryside, town centre, etc), number of roundabout branches; lighting; roundabout shape (oval or round); roundabout radius and traffic volume. A comparison is made between accident rates at these roundabouts and those obtained from 1238 traffic light controlled crossroads. The results indicate that there were twice as many accidents at light controlled crossroads than on roundabouts. However the percentage of accidents involving cyclists and mopeds is almost 60% more on roundabouts. In the larger study of 202 accidents, the accidents are broken down by: (a) type, for example, refusal of priority on entry, pedestrian on ring; and (b) type of road user involved by accident type. Special reference is given to the 85 accidents involving either cyclists and moped riders, and to the 20 accidents involving pedestrians.
Samenvatting