From December 2000 until July 2002, three new speed enforcement initiatives were implemented in Victoria. These initiatives were introduced in stages and involved the following key components: More covert operations of mobile speed cameras, including flash-less operations; 50% increase in speed camera operating hours; and lowering of cameras' speed detection threshold. In addition, during the period 2001 to 2002, the 50 kin/h General Urban Speed Limit (GUSL) was introduced (January 2001), there was an increase in speedrelated advertising including the "Wipe Off 5" campaign, media announcements were made related to the above enforcement initiatives and there was a speeding penalty restructure. The above elements combine to make up a package of speed-related initiatives and factors. The broad aim of this study was to evaluate the overall effectiveness of the speed-related package. This report presents the results of the overall impact during 2001-2004 of the speed-related initiatives on crash outcomes. Evaluation of the crash effects of the Victorian speed-related package has shown clear reductions in the number of casualty crashes associated with its implementation. The package was associated with a highly statistically significant estimated overall reduction in casualty crashes of 3.8%. This reduction was due largely to the highly statistically significant 4.6% estimated reduction in casualty crashes in metropolitan Melbourne. Analysis of the proportion of casualty crashes that were fatal suggested a possible reduction in the risk of fatal outcome in casualty crashes with a non-statistically significant estimated relative crash injury severity of 0.96 whilst analysis of the proportion of fatal or serious injury crashes that were fatal showed a statistically significant reduction in the risk of fatal outcome in the serious casualty crash subset with an estimated relative crash injury severity of 0.86. Both measures of severity showed non-statistically significant estimated reductions in the risk of fatal outcome of 20% for casualty crashes involving pedestrians over the post-implementation period. Since the key component initiatives were implemented in a staggered way, the overall results were partitioned by time in order to assess changes in the crash outcomes over time during the postimplementation period. Because of the staggered implementation, it could be argued that the final partitioned period of July 2004 to December 2004 inclusive best reflects the full effect of the speed-related package on crash outcomes. This period showed a highly statistically significant estimated crash reduction of 10% in casualty crashes, with a non-statistically significant estimated relative crash injury severity of 0.81 occurring for the proportion of casualty crashes resulting in fatal outcome. Compounding these results gave a statistically significant estimated reduction in fatal crashes of 27% with a 95% confidence interval of (5.9%, 48%). Given that 136 fatal crashes were observed during this 6 month period, the number of fatal crashes that would have been expected if the speed-related package had not been implemented was estimated to be 186 (145, 259); this equates to a saving of just over 8 (1, 21) fatal crashes per month. (Author/publisher)
Samenvatting