Single bicycle accident originating from unsuccessful interactions

In Sweden, single accidents are the biggest traffic safety problem for cyclists contributing alone with 80 % of their serious injuries. In this respect, the issue of bicycle infrastructure maintenance received significant attention. Slippery, uneven or in other way problematic road surface is reported as a main contributing factor in about half of the single bicycle accidents [l]. This work explores other causal mechanisms for single accidents, primarily those originating from unsuccessful interactions between cyclists and inftastructure elements as well as other objects and road users on the bicycle path. Interactions with the infrastructure take place at locations of rapid change (often reduction) of the effective space available für cyclists. Such examples could be the narrowing of the bicycle paths at the entrance into a tunnel, speed-reducing gates, parking areas für bicycles and e-scooters, poles, manholes, tree branches and other objects banging over the bicycle paths end forcing cyclists to adjust their travel. In such situations, the cyclist can either collide with the objects directly or lose balance as a result of the rapid speed/direction changes necessary to avoid the collision. Another risk factor is the sharp (and unexpected) tums or lateral displacements of the bicycle path itself that can be observed at the entrances to tunnels (often combined with a steep road descent) or intersections. Collisions between cyclists and pedestrians resulting in severe injuries are relatively few, about 10% of all severe injuries [l]. lt is reasonable, however, to expect that many of such unsuccessful interactions result in single falls rather than direct collisions. lt was shown that about 10% of single accidents bad an interaction with other road users (incl. motor vehicles) as a contributing factor 11]. [from Background]