Why do cyclists violate traffic rules? Evidence for situationally and personally motivated violations, slips, and mistakes from a crowdsourcing project

• We investigate contributions to a crowdsourcing project on cyclists’ safety. • >40 % of the contributions contain references to a traffic rule violation. • Reason’s framework of human error is used to classify the reported violations. • Cyclists tend to feel that situational factors can make a rule violation reasonable. Almost all cyclists violate some traffic rules with varying frequencies; however, there are few direct assessments of their reasons and motivations for these infringements. If we want to tackle traffic rule violations by cyclists as a source of conflict and contra-cycling attitudes, a more complete understanding of the reasons underlying these violations is required. This research is based on a non-representative, web-based inquiry consisting of about 5,800 contributions from road users about traffic situations described as dangerous, confusing, or a nuisance. Contributions were manually coded for the transportation modes of perpetrator(s), victim(s), and the violated rule. Regarding the described or assumed reasons, the classification system of human errors by Reasons was used to differentiate between mistakes, slips and lapses, and routine as well as situational violations. A total of 717 violations committed by cyclists and 1,795 violations committed against cyclists were identified. About half of the contributions expressed or assumed reasons for the described rule violation, only a fraction of which was attributed to recklessness. A noticeable proportion of rule violations by cyclists were attributed to situational factors, suggesting that rule infringements occur because cyclists feel that (i) they have no other choice, (ii) observing the rule is too dangerous, or (iii) traffic regulations are unclear or absent. In order to reduce the rule violations by cyclists as well as their conflicts with other road users, the traffic systems need to be designed such that cyclists do not feel that their most reasonable option is to commit these rule violations.