Victoria introduced a state-wide default 50 km/h speed limit in built-up areas (except where otherwise signed), on January 22, 2001. The purpose of this legislation was to reduce the incidence and severity of crashes involving unprotected road users. The effectiveness of the initiative has been evaluated under a quasi-experimental design framework at various intervals with the last covering a period of almost three years. Results of the final evaluation are presented in this report. Results of the evaluation demonstrate that implementation of the Victorian default 50km/h urban speed limit was associated with reduced casualty crashes in aggregate by around 12% with the reductions sustained over the entire post implementation study period. However, the results also indicate that the program has been more successful in reducing minor injury crashes than in reducing fatal and serious injury crashes. Whilst there was some suggestion of the program being effective in reducing the high severity crashes in the 5 months immediately after program implementation, analysis was unable to identify these effects being sustained over the longer term. Reasons for the lack of measured program effects on high severity crashes were not able to be established from analysis of the limited speed monitoring data available for the evaluation. Assessment of program crash reduction effects for particular road user sub-groups was also carried out in the evaluation. They showed that the change in default speed limit was associated with a sustained reduction in fatal and serious injury crashes involving pedestrians of between 25% and 40%. Effects on crashes involving young drivers were consistent with the overall crash analysis results whilst no significant effects on crashes involving older drivers were measured. (Author/publisher)
Samenvatting