Evidence for the ‘safety in density’ effect for cyclists; validation of agent-based modelling results

Time-gap analysis of cyclists passing through an intersection was conducted using five hours of video-observation of a single intersection in Melbourne, Australia, where motorists were required to ‘yield’ to oncoming cyclists. Results demonstrated that potential collisions between motor-vehicles and cyclists reduced with increasing cyclists per minute in a manner analogous to the SiN effect. These results successfully validate ‘synthetic’ data gathered using agent-based models, supporting evidence of a proposed causal mechanism related to safety in density (SiD) rather than safety in numbers, per se. Results suggest that increased cyclist safety may be achieved through creating high-density strategic cycling corridors.