As far as road safety is concerned, the Walloon Region of Belgium hasconcentrated its action on two fields: the road network and the drivers'behaviour. High-risk sites are detected by means of an automatic method forsearching accident concentrations that is an extended concept of black spots.Once located, each of these sites will be submitted to a multi-criteriaanalysis taking account of the number of victims, geometry, traffic and thefrontage residents' density. Each of these sites then receives a global markindicating the importance of an intervention. The sites concerned areclassified annually according to this mark and the selected sites areanalysed from the accidents' point of view. An efficiency comparison in thencarried on and finally a confrontation with the knowledge of the physicalfield of local authorities and local road managers. When it comes to thedriver the aim is to determine the most frequent mechanical and sociologicalcauses of injury road accidents. An accident is generally due to theconjunction of several factors. Each combination of sociological andmechanical factors defines an accident sequence. The most frequent sequencesthus must be specified in order to know: 1) the mechanical causes (slipperybend, etc); 2) the targets (for instance: young unmarried drivers). Twocomplementary databases are available: the forms filled in by the policeofficers after an accident and the national survey on household mobilitycarried out in 1999. Both of these data sources have variables in common,which allows cross-checking.