Bicycle lanes: Are we running in circles or cycling in the right direction?

BACKGROUND The number of urban bicyclists has grown exponentially across the United States. Bike lanes were created to promote a safe environment for both motorist and cyclists, but few studies have specifically addressed the outcomes of these interventions. The aim of this study was to analyze the effect of bike lanes on bicycle usage and safety in a major urban city. METHODS A retrospective chart review of consecutive adult trauma patients presenting at an urban Level I trauma center due to motor vehicle versus bicycle collisions from January 1, 2007, to January 28, 2017, was performed. Cohorts were stratified into prebicycle and postbicycle lane implementation for analysis. RESULTS Bicycle use during the study period increased almost three fold (1,672 vs. 6,060, p < 0.0001). There was also a spike in the percent of yearly bicyclists as trauma patients during the 10-year period (0.7% vs. 1.5%, p < 0.05). A total of 184 patients brought to the trauma center were identified. Significant differences between the prebike lane and postbike lane groups were identified for average Injury Severity Score (12.7 ± 1.7 vs. 8.0 ± 0.6 p = 0.0134), Glasgow Coma Scale score on arrival (12.6 ± 0.7 vs. 13.9 ± 0.2, p = 0.0171), proportion of head and face injuries (59.4% to 38.8%, p = 0.047), and patients requiring surgical intervention (100% to 55.9%, p < 0.0001). CONCLUSION As bicycle lanes become increasing popular in US cities, it is important to review the success of this intervention on improving safety. Preliminary results from this study suggest that the implementation of urban bike lanes improved bicyclist safety. Further studies should focus on specific injury prevention programs, which could help to target areas such as helmet use and riding a bicycle while impaired to help improve overall safety. LEVEL OF EVIDENCE Prognostic and epidemiological, level IV.