Traffic rule violations by cyclists in the western world: a scoping review

Traffic rule violations by cyclists are fervently discussed in the research community as well as in the general population. Their relevance with regard to traffic safety and conflicts between road users and the situational context in which cyclists commit them remains not fully understood. This review aims to descriptively synthesize the research focusing on specific and spontaneous traffic rule violations by individual cyclists in road traffic. 59 studies were assessed for their methodologies, investigated traffic rules, and violations rates. Surveys relying on cyclists’ self-reported frequency of violations as well as observations based on video-recordings are the most used methodologies. Red-light violations are investigated in about 2/3 of all studies in the scope of this review. Reported violation rates are heterogeneous between methodologies and types of rule violations. Tentative comparisons across studies suggest that the frequencies of some violations reported in observational studies are not necessarily well-aligned with the proportion of cycling-related crashes resulting from these violations types in other studies. Research gaps identified are (1) an evaluation of which traffic rule violations are relevant to study in order to increase cyclists’ safety as well as to reduce conflicts with other road users, (2) a greater focus on integrating different methodologies, and (3) a lack of theoretical frameworks accounting for dispositional, situational, and motivational factors underlying cyclists’ traffic rule violations.