Iranian Journal of

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Background & Objectives: In the chain of vehicles, human and environment, the human factors are the most complex element in the causes of road traffic injuries (RTIs). Unauthorized speeding and overtaking are considered as the main human factors resulting RTIs. This study estimated the population attributablefraction of two human factors, the most common risk factors of rural roads, of RTIs.
 Methods: To calculate the population attributable risk, the prevalence of unauthorized speeding and overtaking registered in Police data was employed. Effect size related to odds ratio was employed using Logistic regression. Joint effect of related risk factors also calculated and reported. Dasta were taken from national traffic police using the KAM 114 froms.
Results: The percentage of population attributable risk of unauthorized speeding for deaths at crash scene was 20.9 and for injured cases was 16.6. These values were 13.5 and 13.4 for unauthorized overtaking respectively. Corresponding for joint effects the population attributable risk was 31.6 for deaths and 27.8 for injuries.
 Conclusion: The results illustrate the importance of speed control and unauthorized overtaking as a priority of RTIs in Iran. It is recommended that related laws and legislations should be pursued more seriously, and followed by more effectively.

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  Background & Objectives : World Health Organization has recommended the main strategies for the prevention of road traffic injuries on some of the risk factors. This study aimed to prioritize the preventive interventions according to risk factors of road traffic injuries in Iran.

  Methods: The potential impact fraction (PIF) of the main strategies for prevention was analyzed from national traffic police data registry in 2011 in urban and rural roads. PIF was calculated for risk factors of road traffic injuries and joint effect at three counterfactual distributions: theoretical minimum risk level, plausible minimum risk level, and feasible minimum risk level. The priority setting of preventive intervention was performed based on contribution of each risk factor.

  Results : Based on the potential impact fraction of death (PIF calculated using odds ratio of death) the priorities were as follows in order: wearing a helmet by the motorcycle passenger, wearing a helmet by motorcycle rider, and lack of speed management. Risk factors in this study were more important in urban roads and joint effects of risk factors were close to 100 percent

  Conclusion: It is strongly recommended that future interventions focus on the use of the helmet by motorcycle passengers and riders, the use of the seat belt by the passengers, and speed management. Our findings indicated that laws and legislations should be pursued more seriously. Calculation of the potential impact fraction is better than the population attributable fraction and allows for more accurate prediction of the future.

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Background and Objectives: Human errors are the most important factors for RTIs, which have been addressed in few quantitative studies. The objective of this study was to calculate the annual population attributable fraction (PAF) of the most important human risk factor for RTIs in the streets and highways of the Great Tehran.
 
Methods: In this study, the data of 124518 individuals registered in the COM114 form of the Police Information and Communication Technology (ICT- FAVA) data system of the country were employed in 2014. A regression model was applied to estimate the magnitude of the impact of traffic violations of drivers with RTIs using the adjusted relative risk ratio. To estimate the PAF, the prevalence and effect size were calculated based on the risk ratio (RR) using the baseline method or the Miettinen formula.
 
Results: The PAF of driving in reverse gear and failure to observe safe distance was 1.98% and 1.93%, respectively. Driving in the reverse gear and failure to observe the safe distance increased RTIs by 22% and 23%, respectively. On the highways of the Great Tehran, the largest proportion of PAF was related to driving in reverse gear (1.96%), sudden movement of the car (1.90%), speeding (1.87%). Speeding increased the risk of RTIs by 23%.
 
Conclusion: Monitoring traffic violations can decrease road crashes by 10% in the streets. Moreover, on highways, use of strategies to prevent traffic violations can decrease RTIs by up to 15%.