Does more cycling also reduce the risk of single-bicycle crashes?
- Correspondence to Paul Schepers, Ministry of Infrastructure and the Environment, Centre for Transport and Navigation, PO Box 5044, 2600 GA Delft, The Netherlands;
- Accepted 18 October 2011
- Published Online First 21 November 2011
Objective This paper examines the relationship between the amount of bicycle use and the number of single-bicycle crashes (ie, only one cyclist involved) in Dutch municipalities. Previous research has focused on crashes between bicycles and motor vehicles; however, most cyclists admitted to hospital are victims of single-bicycle crashes.
Methods This correlational study used three data sets which included data relating to single-bicycle crashes and kilometres travelled by bicycle. Negative binomial regression was used to compare the amount of bicycling with the number of injuries incurred in single-bicycle crashes in Dutch municipalities.
Results The likelihood of single-bicycle crashes varied inversely with the level of bicycle use. The exponent for the change in the number of single-bicycle crashes in response to changes in bicycle volumes was <1 in all analyses (ie, the increase in the number of single-bicycle crashes in a given municipality is proportionally less than the increase in the number of bicycle kilometres travelled by its inhabitants). The value was reduced in analyses of single-bicycle crashes with more severe injuries.
Conclusions Cyclists are less likely to be involved in a severe single-bicycle crash in municipalities with a high amount of cycling. Given the large numbers of patients admitted to hospital as a result of single-bicycle crashes, it is important to include the risks of these in road safety and health effect evaluations, and to take into account the non-linearity of the relationship between single-bicycle crashes and bicycle use if road safety measures are to affect the level of bicycle use.
Funding This research was conducted by the Ministry of Infrastructure and the Environment and received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.