Unveiling Hidden Risks: Using Exposure Data to Reassess Bicyclist Safety on High-Injury Corridors

Abstract

As cities work to develop safer, more connected multimodal transportation networks, prioritizing bicyclist safety has become increasingly critical. Transportation agencies traditionally focus their bicycling safety resources on corridors with high crash numbers. However, this method may overlook streets with fewer crashes but higher risk per bicyclist. Exposure-based safety metrics consider the relative level of bicycling and might offer a more comprehensive understanding of safety. Although standard practice for vehicle road safety work, few cities collect the bicyclist count data needed for similar assessments. This research compared the safety of two corridors: one identified by a hot-spot analysis with a high number of bicyclist–vehicle crashes; and a major arterial in the city’s High Injury Network (HIN), but one that is seemingly safer for bicyclists given the relative scarcity of bicyclist–vehicle crashes. Findings suggest that the HIN corridor, despite fewer bicyclist–vehicle crashes, presented a significantly higher relative risk to bicyclists—when accounting for bicyclist exposure—than the corridor identified via hot-spot analysis. We then examined routes parallel to the HIN corridor to gauge whether bicyclists were avoiding such streets and if collecting additional exposure data on the adjacent streets further enhanced our understanding of safety. Results suggest that bicyclists were avoiding the HIN corridor and that it may be more dangerous than crash-count-focused analyses would reveal. This research underscores the importance of expanding data collection efforts to include exposure metrics for bicyclists, to enhance safety evaluations, guide infrastructural improvements, and support public health by promoting safer, active transportation.