Estimated effects on crashes of lower travelling speeds and speed limits

Abstract

A report has been prepared in response to a brief from Transport SA to further develop the findings from the report by Kloeden et a1 (1997), "Travelling Speed and the Risk of Crash Involvement", in order to provide support for the development of policy in the speed management area. The report develops estimates for casualty crash reductions in the Adelaide metropolitan area from reductions in travelling speeds on various categories of roads. This paper is a summary of that report. Not all of the information needed for the calculation of the estimates of crash reductions was available; some surrogate measures were used. Consequently, although we believe that the estimates presented here are reasonable deductions from the available information, they are dependent in part on certain assumptions, as noted in the text.