Exceeding the speed limit: prevalence and determinants in Iran

Abstract

Speeding is one of the most common risk behaviours associated with crashes causing signficant injury. The objective of this study is to explore the prevalence and determinants of speeding on a road between Tehran and Hamadan, Iran. In a cross-sectional study in 2009, stretches of the road were studied including three groups of posted speed limits: < 50 km/h, 50–100 km/h and > 100 km/h. Each stretch was evaluated both in daylight and dark. Randomly identified driver's speed was checked by a handheld speed camera and then the driver was invited to participate in a survey. Statistical analysis was performed using Chi-Square, crude and adjusted odds ratio, 95% confidence interval and multiple logistic regression models. Overall, 52.8% of the drivers were travelling more than 10 km/h above the posted limit. Where limits were < 50 km/h, 74.6% of drivers were speeding. This declined to 46.9% for sections with limits between 50 and 100 km/h and to 36.9% for sections posted more than 100 km/h. Finally, more than half the drivers were observed to be speeding. Driving more than the posted limit was far more likely on the areas with the lowest posted speed limits, personal passenger vehicles, modern vehicles not using seat belts, and male drivers.

Keywords:

• speeding
• epidemiology
• Iran

Acknowledgements

We appreciate the assistance of Prof. Hamid Shokoohi and Mrs. Bita Pourmand for editing the manuscript and Prof. Soheil Saadat for performing the statistical analysis. This study was supported by grant number 69 – 10.4.2008 of Sina Trauma and Surgery Research Center. First author received the grant. The study protocol was reviewed and approved by Sina Trauma and Surgery Research Center ethical review board.