Background. Risk of road crash injuries is unclear, partly because of under-reporting and bias in the police crash data, partly because of lack of mobility (exposure) data. Methods. Injury incidence rates were estimated. Accident data come from a road trauma Registry, including outpatients and inpatients, on the Rhône county (1.6 M inhab.). Mobility comes from a travel survey. It was carried out from November 2005 to April 2006, on weekdays; this seasonality was corrected using the 2007-2008 national travel survey. Results. Compared with car occupants and with regards to time spent travelling, the all-injury rate was 8 times higher for cyclists, twice lower for pedestrians and 42 times higher for PTW riders; the hospitalization rate was the same for pedestrians, 12 times higher for cyclists and 80 times higher for PTW riders; the fatal-injury rate was the same for pedestrians, 3 times higher for cyclists and 34 times higher for PTW riders. Cyclists had lower injury rates in towns than outside towns. Between 1996-1997 and 2005-2006 and with regards to time spent travelling, the all-injury rate was multiplied by 0.9 for car occupants, by 0.4 for cyclists and by 1.3 for PTW riders. Conclusion. The higher risk for PTW riders is confirmed and quantified; it is very high. Decrease in injury rates was more marked for cyclists; this indicates the "safety in numbers" effect.
