Assessing the impact of road safety agencies and health systems in traffic outcomes across 146 countries, 1994-2012.

BACKGROUND: Road safety policies (RSPs) have emerged worldwide. Yet, while an important group of RSPs have been regarded as necessary to reduce traffic crashes and their consequences, the impact of others remain inconclusive. To advance knowledge on this debate, this article focuses on the potential effects of two RSPs: i) road safety agencies (RSAs) and ii) health systems (HS). METHODS AND DATA SOURCES: Cross-sectional longitudinal data corresponding to 146 countries from 1994 to 2012 are analyzed using regression models to account for the endogeneity of RSA formation, including instrumental variable and fixed effects designs. A global dataset compiling information from multiple sources, including the World Bank, and the World Health Organization is built. RESULTS: RSAs are associated with a decrease of traffic injuries in the long-term. This trend is observed in Organisation for Economic Co-operation and Development (OECD) countries only. Potential data reporting differences between countries could not be accounted for, and therefore it is unclear whether the observation for non-OECD countries is due to an actual difference or due to these reporting differences. HSs decrease traffic fatalities by 5% (95% Confidence interval (CI) 3% to 7%). Across (OECD) countries, HS is not associated with traffic injury variation. CONCLUSION: While some authors have theorised that RSA institutions may fail to reduce either traffic injuries or fatalities, our work however captured a long-term effect in RSAs performance when targeting traffic injury outcomes. That well-developed HSs have been effective in decreasing traffic fatalities, and ineffective in decreasing injuries, is consistent with the overall function that this type of policies fulfils. Results call for revisiting the specific mechanisms which explain why RSAs and HSs seem effective in decreasing different traffic outcomes.

Did Chile's traffic law reform push police enforcement? Understanding Chile's traffic fatalities and injuries reduction.

BACKGROUND: The objective of the current study is to determine to what extent the reduction of Chile's traffic fatalities and injuries during 2000-2012 was related to the police traffic enforcement increment registered after the introduction of its 2005 traffic law reform. METHODS: A unique dataset with assembled information from public institutions and analyses based on ordinary least square and robust random effects models was carried out. Dependent variables were traffic fatality and severe injury rates per population and vehicle fleet. Independent variables were: (1) presence of new national traffic law; (2) police officers per population; (3) number of traffic tickets per police officer; and (4) interaction effect of number of traffic tickets per police officer with traffic law reform. Oil prices, alcohol consumption, proportion of male population 15-24 years old, unemployment, road infrastructure investment, years' effects and regions' effects represented control variables. RESULTS: Empirical estimates from instrumental variables suggest that the enactment of the traffic law reform in interaction with number of traffic tickets per police officer is significantly associated with a decrease of 8% in traffic fatalities and 7% in severe injuries. Piecewise regression model results for the 2007-2012 period suggest that police traffic enforcement reduced traffic fatalities by 59% and severe injuries by 37%. CONCLUSIONS: Findings suggest that traffic law reforms in order to have an effect on both traffic fatality and injury rates reduction require changes in police enforcement practices. Last, this case also illustrates how the diffusion of successful road safety practices globally promoted by WHO and World Bank can be an important influence for enhancing national road safety practices.

Explaining Chile's traffic fatality and injury reduction for 2000-2012.

OBJECTIVES: The objective of the current study is to determine the contribution of Chile's 2005 traffic law reform, police enforcement, and road investment infrastructure to the reduction of traffic fatalities and severe injuries from 2000 to 2012. METHODS: Analyses based on structural equation models were carried out using a unique database merging aggregate administrative data from several Chilean public institutions. The sample was balanced (13 regions, over 13 years; N=169). Dependent variables were rates of traffic fatality (total, drivers, passengers, and pedestrians), severe injuries, and total number of crashes per vehicle fleet. Independent variables were (1) traffic law reform, (2) police enforcement, and (3) road infrastructure investment. Oil prices, alcohol consumption, proportion of male population 15-24 years old, unemployment, years' effects and regions' effects, and lagged dependent variables were entered as control variables. RESULTS: Empirical estimates from the structural equation models suggest that the enactment of the traffic law reform is significantly associated with a 7% reduction of pedestrian fatalities. This association is entirely mediated by the positive association the law had with increasing police enforcement and reducing alcohol consumption. In turn, police enforcement is significantly associated with a direct decrease in total fatalities, driver fatalities, passenger fatalities, and pedestrian fatalities by 17%, 18%, 8%, and 60%, respectively. Finally, road infrastructure investment is significantly associated with a direct reduction of 11% in pedestrian fatalities, and the number of total crashes significantly mediates the effect of road infrastructure investment on the reduction of severe injuries. Tests of sensitivity indicate these effects and their statistical significance did not vary substantively with alternative model specifications. CONCLUSIONS: Results suggest that traffic law reform, police enforcement, and road infrastructure investment have complex interwoven effects that can reduce both traffic fatalities and severe injuries. Though traffic reforms are ultimately designed to change road user behaviors at large, it is also important to acknowledge that legislative changes may require institutional changes--that is, intensification of police enforcement--and be supported by road infrastructure investment, in order to effectively decrease traffic fatalities and injuries. Furthermore, depending on how road safety measures are designed, coordinated, and implemented, their effects on different types of road users vary. The case of Chile illustrates how the diffusion of road safety practices globally promoted by the World Health Organization and World Bank, particularly in 2004, can be an important influence to enhance national road safety practices.