SHORT TERM EVALUATION OF SAFETY COUNTERMEASURES. TWO EXAMPLES OF EXPERIMENTS WITH SPEED-REDUCING COUNTERMEASURES IN SWEDEN

The need for surrogates to accidents for the evaluation of accident-risks resulted in the development of a traffic conflicts technique at the department. The technique was first presented in 1976. Modifications have been made during the last years and now a project is on-going aiming at validating a new technique with a modified definition of a serious conflict. International cooperation in the area is established and joint activities are planned aiming at comparing techniques developed in different countries. The paper also deals with the extensive research work that is under way at the department on the effects of actual speed reductions in urban areas. The speed reduction is achieved by physical measures such as humps, etcetera. Experiments are carried out on different types of streets, ranging from local residential streets to arterial streets carrying ten to fifteen thousand vehicles a day. The results so far are very promising and it seems as if speed reduction is a very interesting complement or alternative to the traffic safety measures traditionally used. (Author/TRRL)