Statement of purpose Bicycling is becoming a popular mode of transportation within the United States. Due to the increase of cyclists/vulnerable road users, laws and safety recommendations are being established to keep all road users safe. The purpose of this study was to observe bicycle safety behaviours and road law compliance of personal and bike share users at several high traffic intersections in Boston, MA.

Methods/Approach This is a prospective observational study of safety and law compliance behaviours of bicyclists in downtown Boston. Investigators observed bicyclists for specific law and safety compliance behaviours including: wearing a helmet, riding in bike lanes, displaying reflectors at night, and obeying all road laws. The findings of this study were compared to other national and international studies that observed bike share and personal bike users.

Results 1685 cyclists were observed. Of all observations, 74% of all bikers wore a helmet and 83% obeyed the road laws. 39% bike share riders and 78% of personal bikers were observed wearing a helmet (p = 0.0001). A sample of 680 cyclists was observed for obedience with mandated reflector laws at night and 39% were in compliance (p = 0.001).

Conclusions Boston bicyclists were more compliant with helmet use and road law compliance as compared to prior studies in the US and Canada. The majority of cyclists demonstrated safe cycling practices, however other unsafe cycling behaviours were noted and merit further investigation (i.e. distracted biking). Bicycling is common mode of daily transportation, and more observational studies and interventional studies are needed to assess and mitigate emerging risks for bicyclists in today’s society.

Significance and contribution to the field This is one of the first comprehensive bike observation studies in the city of Boston that provides data on multiple cycling safety behaviours. Based on our observations, the use of electronic devices while biking is widespread and requires further investigation.