Frequency and Legitimacy of Aggressive Driver Behaviour against Cyclists when Sharing the Road

Cyclists' perception of car drivers as 'aggressive' and potentially dangerous is an important reason why they demand dedicated cycling infrastructure or cycle on the footpath even when it is illegal. Cycling infrastructure is built on main roads only. On minor roads cyclists and drivers share the road which might lead to conflicts. We tried to explore such a situation from the perspective of a car driver who drives behind a cyclist and has no opportunity to overtake with the legal safety margin. In such a situation, drivers have several options to react. The only legal option is to adapt their own speed to the cyclist's speed, wait until there is enough room and overtake then. Some drivers show other reactions which might frighten the cyclist and/or increase the risk of a crash: honking, shouting, close following, close overtaking and others. Cyclists might avoid roads where they made or expect such experiences, cycle on the footpath, cycle in the dooring zone of parking cars. Noncyclists observing such driver behaviour might decide better not to cycle at all. These reactions work against the political aims to increase the modal share of cycling and walking and improve traffic safety for nonmotorized road users. What are the differences between drivers who perform actions which are aggressive more or less often? Which role do their attitudes and mobility habits play? We expected that drivers who see cyclists on the road as less legitimate perform more aggressive acts [1, Oldmeadow]. We expected a positive correlation between perceived legitimacy of aggressive acts and the frequency of their performance. Road users have different general aims lik.e speed and safety. There are also more situation specific aims like expressing one's anger. We expect that drivers see behaviour which is in accordance with their aims as more legitimate [2, Varet] and show it more often. We expect that car drivers who show more aggressive behaviour blame cyclists more for the situation [3, Pimentel]. We expect that persons who cycle more often behave in a less aggressive manner because they see the situation also from the perspective of the cyclist. Aggressive drivers commit more traffic violations [4, King] and thus have a higher risk of receiving a fine. We expected that persons who report more aggressive behaviour have got more fines for traffic offences. [From: Introduction