The safest roads in a road network are motorways and local streets with traffic calming. Most of the accidents occur on the other roads, which form the larger part of the network. So for safety reasons motorized traffic should be encouraged to use motorways and should be discouraged to use local streets. However, much traffic will (therefore) use the intermediate roads, which have high accidents figures. These intermediate roads are mostly meant for distribution (to and from areas), as well as for local access. It is very difficult to separate these two traffic functions in such a way that the roads can still be important veins in the road network while being sufficiently safe at the same time. How can proposals for adapting these types of roads be judged on the safety consequences? Estimation of these consequences should be possible in all stages of the life cycle of a road or street (planning, design, construction, redesign, and reconstruction). A first estimation, of a qualitative nature, is made by a Road Safety Audit: it gives an expert judgement. The results of the estimation or test are more objective when a proposal is evaluated according to a set of safety requirements. These requirements aim at preventing different accident types, e.g. preventing accidents with opposing vehicles is achieved by the requirement that opposing directions should be separated physically. Tests with these sorts of requirements are currently being performed in the Netherlands. The experiences were compared to outcomes of Road Safety Audits.
Testing the safety level of a road network
Contribution to the XXIIth PIARC World Road Congress, 19-25 October 2003, Durban, South Africa