Estimating the safety benefit of separated cycling infrastructure adjusted for behavioral adaptation among drivers; an application of agent-based modelling

Separated cycling infrastructure is a key strategy employed by urban and transport planners to reduce car vs cyclist crashes. We constructed an agent-based model (ABM) to explore the potential effects of introducing progressively greater levels of saturation (e.g., more km) of separated cycling infrastructure into a transport network in which drivers also demonstrated behavioral adaptation in response to increased exposure to cyclists as suggested by the safety in numbers (SiN) theory. The findings highlight that if behavioral adaptation among drivers is assumed to be a strong mechanism underpinning cyclist safety, the introduction of low levels of separated cycling infrastructure across a network (e.g., few km) may provide little or no reduction in car vs cyclist crashes.