Characteristics of unsafe events involving a motor vehicle for group riders in Western Australia: A naturalistic study

Little is known about the safety issues affecting non-professional group riders. This study aimed to identify the most common unsafe events involving a motor vehicle that occurred while group riding, describe their characteristics and suggest potential preventative measures. A naturalistic study collected video footage from cameras attached to the bicycles of group riders who rode on-road for training, fitness or recreation in Perth, Western Australia. Fifty-two riders from 40 different riding groups, recorded footage of 126 group riding trips, resulting in 135 h of video. A total of 108 unsafe events (‘near-crashes/ crash relevant events’ and ‘close passing only events’) involving the group riders and a motor vehicle were observed. The most common type of unsafe event involved a motor vehicle attempting to pass/ overtake the group (65.7%). For 39.4% of the passing events, the presence of road infrastructure ahead (e.g. roundabout, traffic island) prevented safe passing and led to an unsafe event. Motorists were at fault for 83.3% of all unsafe events and reckless behaviour by the motorist was observed for 13.3% of these at-fault events. Aggressive communication on the part of the motorist or rider/s was observed for 15% of all unsafe events. This study highlighted that motorists were at fault for the majority of unsafe events involving group riders but only a small proportion involved reckless behaviour. Further research should examine the effectiveness of motorist education as well as infrastructure modifications on popular group riding routes, for reducing unsafe events involving group riders.