Bicycle paths are safe on road sections but problems arise at intersections. The aim of the present study was to investigate factors in road user behaviour, traffic environment and rules, which affect accidents between bicyclists and car drivers. Accident analysis and unobtrusive video recordings were conducted in five studies in order to develop methods to estimate the relationship between behaviour in accidents and in normal traffic. The behaviour of road users was measured in terms of approaching speed, head movements and how they yielded in different traffic situations. The most frequent accident type among collisions between cyclists and cars at bicycle crossings was a driver turning right and a bicycle coming from the driver's right along a cycle track. This accident type comprises about 20% of all bicycle crossing accidents between bicycles and cars. A comparison of accident types in various conditions indicated that the risk of bicycle-car collisions is 10 times higher at bicycle crossings with restricted visibility than with corresponding crossings without sight obstacles. The most frequent accident type was closely related to the system of two-way cycle paths and to the priority regulations when a cyclist with right-of-way may appear unexpectedly from driver's point of view. The results confirm that the problem of the driver turning right and the cyclists coming from the right is also most acute at roundabouts. The data collected in Finland, Sweden and Denmark showed that 14% of drivers did not look at all cyclists who were approaching the bicycle crossing from the right, on a collision course. In reducing bicycle-car collisions specific consideration should be given to the principle that the traffic environment should guide road users to follow the traffic rules. This has uttermost importance, because at intersections drivers tend to look first for other cars, which are normally more numerous than cyclists and also pose a more severe threat of collision. Furthermore, the behaviour of cyclists seems to be more dependent on roadway widths and motor traffic volumes and speeds, rather than the traffic rules. (A)
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