Background Recently, different Mexican cities have implemented public policies on sustainable mobility, including the promotion of bicycle as means of transport. It is not evident to what extend policies include measures to promote road safety and thus we expect road traffic injuries (RTI) will increase in this road user. To inform these policies, we analysed RTI amongst cyclist as well as helmet use.

Methods Analysis of 4 secondary databases: preliminary mortality figures, Ministry of Health hospital discharges (50% of all hospital discharges in the country), ER and hospital statistical registries (SIS-17), and the 2012 National Health and Nutrition Survey (ENSANUT), representative at the national level. Only ENSANUT and SIS-17 report helmet use. Except for ENSANUT information analysed is of 2014, the latest information available.

Results Deaths: 138 (1% of all RTI); 97% male, 65% died on the scene, mean age = 46. Most severe injuries were in the head (68%), thorax (11%) and multiple regions (9%). Hospitalizations: 392 (1% of RTI), 83% male, mean age = 33. Main injury was in the head (32%), leg (17%) and multiple regions (12%). SIS-17: 667 cyclists were recorded, 80% male, mean age = 30. Helmet use was not recorded in 71%, when specified 2.6% reported its use. Most severe injury was multiple regions (29%), head (21%), and leg (10%). ENSANUT: estimated 165,348 cyclists not-fatally injured, 87% male, mean age = 25, SE = 3.6, 9.8% used helmet. Region most affected was leg (38%), arm (35%) and head (23%). Although no helmeted cyclists reported head injuries vs 24% amongst non-helmeted, difference was not statistically significant.

Conclusions Head injuries are common among cyclists and helmet use is low. Whereas cyclist-friendly infrastructure is an effective intervention to prevent injuries in the long term, helmet use could potentially reduce the frequency and severity of head injuries in the short run while bicycle widespread as a means of transport provides “safety in numbers”.