This paper examines how changes in road infrastructure and road use can provide a safer environment for all road users, whatever their mode of travel or age. A brief statistical summary is given of the main features of road accidents in Great Britain, with respect to road user casualties, vehicles involved, and accident circumstances. A table lists the main accident types on roads in general, urban roads, and rural roads, and, for each type, specifies the remedial option(s) and the resulting potential savings in accidents. Accidents are reduced by applying cost-effective measures on existing roads, and prevented by applying safety principles to the provision, improvement, and maintenance of roads. Hazardous road locations extend far beyond 'blackspots' to include a wide range of locations and situations. The investigatory techniques adopted are: (1) single sites; (2) mass action on locations with common accident factors; (3) route action on road sections with above-average accident rate for their type; and (4) area action on areas needing a global approach. In each case, the investigation process identifies problem locations, diagnoses the problem, and selects, implements, and evaluates remedial measures. Examples of treatments are described for each type. Finally, some priorities for future action are identified.