Cyclist safety: an investigation of how cyclists and drivers interact on the roads

Cyclists are vulnerable road users and the most severe injury outcomes for on-road cyclists are from collisions involving a motor vehicle. Research undertaken in this thesis aimed to identify contributing factors in unsafe cyclist-driver events to inform efforts to reduce the incidence of cyclist-driver crashes and cyclist injury severity outcomes. The research was conducted in three stages, primarily in Melbourne, Victoria, Australia and is presented as a thesis by publication. The Safe System Framework was used as the theoretical model for the research and the research stages included i) an observational study using a covertly positioned video camera at signalised intersections across metropolitan Melbourne; ii) a naturalistic cycling study using a compact video camera attached to commuter cyclists’ helmets which recorded their trips to and from work; and, iii) a national online survey of drivers and cyclists of their cycling-related behaviours, knowledge and attitudes. The role of driver behaviour in cyclist-driver crashes and near-crash events was identified and was the most significant finding of this doctoral research. In-depth analysis of near-collision events revealed that drivers’ behaviour immediately prior to an event contributed to the majority of unsafe interactions between cyclists and drivers. The most frequent driver behaviour associated with near-collision events was turning left across a cyclists’ path. Three important components of this behaviour were: indicating (signalling) before turning, driver head checks before turning left and clearance distance when overtaking cyclists. These three behavioural components were investigated further, with a particular focus on the influence of cycling-related knowledge and attitudes. Findings supported the concept of safety in numbers which proposes a positive association between cycling participation and cyclist safety. A significant finding was that drivers who were also cyclists (driver-cyclists) were more likely than drivers who were not cyclists to report safe driving behaviours. Driver-cyclists also reported more positive attitudes towards cyclists and good knowledge of road rules for cycling facilities. Cyclist behaviour had also been identified as a potential crash risk factor, particularly red light running behaviour. Encouragingly, however, only a small proportion of observed cyclist infringed and predictive factors included direction of travel (left turn) and gender (male). The presence of other road users (cross traffic and in the same direction) had a deterrent effect. Last, the presence of cycling facilities was associated with cyclist-driver interactions. Cyclist and driver behaviour at two cycling facilities at intersections (bike boxes and continuous bike lane) was measured. Despite the high level of knowledge of bike boxes, many drivers were non-compliant at this type of facility. In contrast, both cyclists and drivers were more likely to be compliant at the facility that provided a continuous parallel bike lane compared with the bike box facility. Findings of this research provide new insights into the influence of behavioural factors and presence of cycling facilities on cyclist safety. Greater cyclist-related driver education and training are essential to improve cyclist safety. It is anticipated that the findings from this research will inform programs and initiatives that will improve the safety of on-road cyclists