The contribution of infrastructure characteristics to bicycle crashes without motor vehicles : a quantitative approach using a case-control design. Master thesis Delft University of Technology.

Cycling is one of the main transport modes in the Netherlands and the total number of bicycles and the total cycling distances are still rising. Although this seems a positive development, the number of seriously injured cyclists due to bicycle crashes without motor vehicles increased rapidly in recent years. Within these crashes the infrastructure seems to play an important role and research towards the contribution of infrastructure characteristics to bicycle crashes without motor vehicles is needed because this is limited and especially research on more detailed infrastructure characteristics (e.g. bicycle path width) has not been done yet. This study aims to fill in parts of the knowledge gap between the safety problem and the lack of research done on the contribution of infrastructure characteristics. This study was done by using data from a survey held by VeiligheidNL. In total, 3146 cyclists that were treated at an emergency department responded to the survey and provided information on the crash location and the trip origin. A case-control method was applied in this study which compared infrastructure characteristics of case (crash) and control locations (no crash). The control locations were selected from the route of a bicycle crash victim. The design of the method included basic steps for the selection of the controls and four measures to lower the bias in the method and increasing the statistical power of the results. With the application of the case-control method to the data several results were found: First, the width of streets contributes to riding off the road crashes and handlebar collisions, whereas the width of bicycle paths next to bollards contributes to crashes with these objects. Secondly, the presence of intersections decreases the likelihood of kerb collisions. Thirdly, two-directional bicycle paths are more likely to induce bicycle-bicycle crashes and they possibly induce more severe crashes because frontal collisions were found more severe than same direction bicycle-bicycle crashes. And finally, the placement of bollards increases the severity of the injuries caused by the corresponding crashes. These findings could be used to further increase the quality of bicycle design guidelines such that future bicycle infrastructure could be designed safer. (Author/publisher)