Impacts of urban road layout on road safety: how to evaluate?

Road layout improvements aim to reduce the use of cars and to develop alternative means of transport, but what about their impacts on road safety? Nowadays, road managers could rightfully ask this question. One solution is to realise an evaluation of road safety in road layout improvements. Then, how to evaluate? As there is little literature on this subject, this article presents a method built within the PREDIT research program framework. This method is based on several existing approaches which are used rarely together: quantitative approach of road safety and qualitative approach of road safety with the help of accident scenarios, a detailed analysis of the road layout and analysis of uses and practices on am outfitted site. A cross-analysis enables one to identify points of convergence and divergence in all approaches; it enables one also to connect road safety problems with the way of using public space. For instance, the method was tested on seven road layout improvements. The results point out such problems as a lack of consideration for pedestrians, difficulty for two-wheelers to integrate traffic when public transport lane involves road width reduction, and the wrong use of cycle lanes (for delivery, parking, etc.).