Public bike sharing in New York City: helmet use behavior patterns at 25 Citi Bike™ stations.

Urban public bicycle sharing programs are on the rise in the United States. Launched in 2013, NYC's public bicycle share program, Citi Bike™ is the fastest growing program of its kind in the nation, with nearly 100,000 members and more than 330 docking stations across Manhattan and Brooklyn. The purpose of this study was to assess helmet use behavior among Citi Bike™ riders at 25 of the busiest docking stations. The 25 Citi Bike™ Stations varied greatly in terms of usage: total number of cyclists (N = 96-342), commute versus recreation (22.9-79.5% commute time riders), weekday versus weekend (6.0-49.0% weekend riders). Helmet use ranged between 2.9 and 29.2% across sites (median = 7.5 %). A total of 4,919 cyclists were observed, of whom 545 (11.1%) were wearing helmets. Incoming cyclists were more likely to wear helmets than outgoing cyclists (11.0 vs 5.9%, p = .000). NYC's bike share program endorses helmet use, but relies on education to encourage it. Our data confirm that, to date, this strategy has not been successful.