As far as road safety is concerned, the Walloon Region of Belgium has concentrated its action on two fields: the road network and the drivers' behaviour. High-risk sites are detected by means of an automatic method for searching accident concentrations that is an extended concept of black spots. Once located, each of these sites will be submitted to a multi-criteria analysis taking account of the number of victims, geometry, traffic and the frontage residents' density. Each of these sites then receives a global mark indicating the importance of an intervention. The sites concerned are classified annually according to this mark and the selected sites are analysed from the accidents' point of view. An efficiency comparison in then carried on and finally a confrontation with the knowledge of the physical field of local authorities and local road managers. When it comes to the driver the aim is to determine the most frequent mechanical and sociological causes of injury road accidents. An accident is generally due to the conjunction of several factors. Each combination of sociological and mechanical factors defines an accident sequence. The most frequent sequences thus must be specified in order to know: 1) the mechanical causes (slippery bend, etc); 2) the targets (for instance: young unmarried drivers). Two complementary databases are available: the forms filled in by the police officers after an accident and the national survey on household mobility carried out in 1999. Both of these data sources have variables in common, which allows cross-checking.