The use of conspicuity aids by cyclists and the risk of crashes involving other road users: a population based case-control study

Regular cycling has been shown to improve health and well-being and has a role in tackling obesity and inactivity.

Cycle collisions, particularly those involving motorised vehicles, can lead to significant mortality and morbidity and are currently a barrier to wider uptake of cycling.

There is evidence that the conspicuity of cyclists may be a factor in some injury collisions. Low-cost, easy to use retro-reflective and fluorescent clothing and accessories (’conspicuity aids’) are widely available. Their effectiveness in reducing the risk of cycling collisions is currently unknown. This study was designed to investigate the relationship between the use of conspicuity aids and risk of collision or evasion crashes for utility and commuter cyclists in an urban setting in the UK.

The results of this study show a non-significant increase in the odds of a crash for users compared to non-users of conspicuity aids whilst cycling. This association was increased after adjustment for confounders but most models generated to adjust for confounding remained insignificant. No reduction in crash risk could be demonstrated.

This is not consistent with the large body of evidence suggesting that conspicuity aids increase the distances from which wearers can be detected and recognised by drivers in a variety of settings.

This study demonstrates the importance of understanding why many cyclists remain at risk of collision crash resulting in injury despite the use of conspicuity aids.