Reducing road traffic injuries: effectiveness of speed cameras in an urban setting. The crash reduction effectiveness of a network-wide traffic police deployment system. Controlled evaluation of a community based injury prevention program in Australia.
We assessed the effectiveness of speed cameras on Barcelona's beltway in reducing the numbers of road collisions and injuries and the number of vehicles involved in collisions.
                We designed a time-series study with a comparison group to assess the effects of the speed cameras. The "intervention group" was the beltway, and the comparison group consisted of arterial roads on which no fixed speed cameras had been installed. The outcome measures were number of road collisions, number of people injured, and number of vehicles involved in collisions. We fit the data to Poisson regression models that were adjusted according to trends and seasonality.
                The relative risk (RR) of a road collision occurring on the beltway after (vs before) installation of speed cameras was 0.73 (95% confidence interval [CI]=0.63, 0.85). This protective effect was greater during weekend periods. No differences were observed for arterial roads (RR=0.99; 95% CI=0.90, 1.10). Attributable fraction estimates for the 2 years of the study intervention showed 364 collisions prevented, 507 fewer people injured, and 789 fewer vehicles involved in collisions.
                Speed cameras installed in an urban setting are effective in reducing the numbers of road collisions and, consequently, the numbers of injured people and vehicles involved in collisions. Random Road Watch (RRW) is a traffic policing program in operation in Queensland, Australia. It differs from conventional traffic policing in that an explicit resource management technique is used which randomly schedules low levels of police enforcement in a manner intended to provide long-term, widespread coverage of a road network and hence maximise road safety benefits. Implementation of the program studied in Queensland covered 55% of total crashes within the state. This study aimed to measure the crash effects of the RRW program in Queensland. A quasi-experimental study design was used for the evaluation incorporating Poisson regression statistical analysis techniques. Analysis of the effects of the Queensland RRW program on crash frequency has shown the program to be effective overall. Estimated program effects were largest on fatal crashes, with an estimated reduction of 31%. Estimated aggregate program crash effects reduced with crash severity and increased with time after program introduction. Crash reductions in the third year after program introduction translated into savings, at state level, of some 12% of the state's crashes of all severities and some 15% of the state's fatal road crashes. Overall, the program produced a significant 11% reduction in total crashes in areas outside of metropolitan Brisbane. The opportunity-cost benefit/cost ratio for the program was estimated to be 55:1. To evaluate the effects of a community based, all age, all injury prevention program, the Safe Living Program, on injury risk and injury rates.
                A quasiexperimental population based evaluation using an intervention and comparison community design.
                The intervention community (Shire of Bulla, n = 37,257) is an outer metropolitan area of Melbourne, Australia. The demographically matched comparison community (Shire of Melton, n=33,592) is located nearby.
                The Safe Living Program in the Shire of Bulla targeted injury reduction in all settings with a focus on high risk groups. Strategies included program publicity, education and training, injury hazard reduction, and environmental change. Baseline and follow up measures of program reach, risk factors, and injury rates in both communities were used to evaluate program process, impact, and outcome.
                Increase in program awareness was moderate and similar to other community based programs. The program achieved injury hazard reduction on the road, in schools, and, to a more limited extent, in the home. Other changes in injury risk factors could not necessarily be attributed to the program as similar changes were observed in the comparison community. No significant changes were found in rates of injury deaths, hospitalisations, or emergency department presentations in the Shire of Bulla after six years. Self reported household injuries, mostly minor, were reduced in the intervention community, but had been higher at program launch than in the comparison community.
                The Safe Living Program was unable to replicate the significant reductions in injuries reported in other community based interventions. Replication of apparently successful community based injury prevention programs in different settings and populations requires evidence based interventions, sustained and effective program penetration, reliable data systems to measure change, at least one control community, and sufficient budget and time for effects to be observable.
The results from this review suggest that area-wide traffic calming in towns and cities may be a promising intervention for reducing the number of road traffic injuries and deaths. However, further rigorous evaluations of such interventions are needed.