Do Bike Sharing Programs Increase the Risk of Head Injuries?

While many have applauded the rise of public bike sharing programs (PBSPs) in major cities as an attractive transportation source, a new study shows that the bike programs may be significantly increasing risks for head injuries. In short, the study found that “the proportion of head injuries among bicycle-related injuries increased from 42.3 [percent] before the PBSP implementation to 50.1 [percent] after…” in cities that adopted PBSPs, which typically do not offer helmets along with the bike rental. After the study’s release and the publication of many pieces commenting on the studies’ results, yet other sources were quick to point out that the media’s coverage of the study misinterpreted its results and argued that, overall, PBSPs actually decreased the risk of head injuries.


Many larger cities have adopted PBSPs including Boston, Denver, Miami, Minneapolis, and Washington, D.C. According to, these bike programs offer subscriptions that entail “anything from a day pass ($5 to $10) to an annual membership ($60 to $75). Then, you visit a kiosk, swipe a credit card, use a key, or punch a code to check out a bike.” Typically rides are timed and overage charges accrue for rides that exceed 30 minutes in duration. The notes that although PBSPs are a rising “environmentally friendly, health-conscious transport alternative,” one major problem associated with the public biking movement has been identified: “it’s much easier to create a system of communal bikes than a system of communal helmets.”


The specific objective of the PBSP study, which was published in the American Journal of Public Health, was as follows: to evaluate “the effect of North American [PBSPs], which typically do not offer helmets with rentals, on the occurrence of bicycle-related head injuries.” To assess this correlation, the study’s authors collected data from trauma centers in five cities that had adopted PBSPs, including Washington, D.C., Boston, Miami Beach, Montreal, and Minneapolis, and compared that data with statistics based on information collected in cities that did not have such programs. The Washington Post characterized the study’s findings as follows: that researchers “found a 14 percent greater risk of head injuries to cyclists associated with cities that have bike share programs.” The Post also noted that, currently, no PBSP offered bike helmets, yet it noted that some cities, like Seattle where there is a law that requires cyclists to wear helmets, plan to introduce helmets into the sharing programs soon. In contrast, most other cities do not have plans to adopt a helmet sharing aspect to accompany the bike sharing system.


A article asserted that most of the coverage of the PBSP study misinterpreted the meaning of the findings. Specifically,  the Vox article alleged that the  media claim that bike-share programs led to an increase in head injuries was wrong. Instead, Vox stated the first finding of the study’s authors is more important but “it was largely ignored in the initial round of coverage.” In other words,  because the PBSP encouraged bike riding, the overall numbers of head injuries incurred by cyclists has declined while the number of miles biked in cities with PBSPs increased. The Smithsonian had a similar take on the story as it reported that, “cities with bike shares have fewer bike-related injuries overall,” but also noted that, “a higher proportion of bike-related injuries are head-related injuries—but these cities have fewer head injuries, too.” While Vox has previously  advocated for no-helmet biking, the Smithsonian highlights the important point that PBSPs encourage more bikers on the road, which also will reduce injuries overall. Yet, in the end, the Smithsonian echoed the recommendations of the study’s authors: that PBSPs should  include helmets in the sharing systems from the beginning.