Drivers who don't comply with a minimum passing distance rule when passing bicycle riders

Drivers' passing cyclists closely can contribute to crashes, falls, and intimidation, which may discourage cycling. In response, minimum passing distance (MPD) rules have been introduced in many jurisdictions. This study examined the factors associated with non-compliance with a MPD rule.

An online survey of 3,769 drivers in Queensland, Australia was administered 1 year after a MPD rule began. It assessed compliance with and attitudes toward the rule. Linear regression modeling was used to examine which attitudinal and demographic factors were associated with non-compliance.

The percentage of drivers who reported that they did not comply with the road rule "most of the time" or "almost always" was 35.5% in speed zones of ≤60 km/h and 31.8% in speed zones of >60 km/h. Associated with a greater likelihood of being non-compliant were: only infrequently observing motorists giving bicycle riders more distance when overtaking; greater awareness of bicycle riders when driving on the road; disagreeing that the rule had changed the person's driving; agreeing that the rule was making overtaking bicycle riders difficult; disagreeing that the rule had made it safer for bicycle riders; agreeing that it was difficult to judge 1 or 1.5 m when overtaking a bicycle rider; and agreeing that giving 1.5 m clearance in >60 km/h zones to bicycle riders was annoying (p < .05). In high speed zones, drivers aged 18-39 years were more likely than those aged 50+ years to be non-compliant (p < .05). Compliance was not associated with driver sex, amount of driving, or perceived level of enforcement.

Reported non-compliance with the MPD rule is widespread and is related more to attitudinal than demographic factors. Practical applications: Strategies for helping drivers to judge passing distance and improve their understanding of the importance for cyclist safety of leaving an adequate distance are needed.