The concept of sustainable traffic safety is used in the Netherlands and  usually it includes the following: 1) an infrastructure whose design is  adapted to the limitations of human capabilities; 2) vehicles equipped to  facilitate human tasks and constructed so as to optimally protect people,  vulnerable as they are; and 3) traffic participants who are adequately  educated, informed and, where necessary, monitored. The paper details the  concept especially when it comes to the categorisation of the road network  using different criteria.