International Journal of Transportation Engineering

International Journal of Transportation Engineering

Evaluation of Safety Measures on the Highways of Isfahan Province Based on before-and-after Studies using the Experimental Bayes Method

Document Type : Research Paper

Authors
Mohammadali Salavati
Jafar Jamili
PhD Candidate in Civil Engineering, Transportation Planning University of Tehran
10.22119/ijte.2025.504189.1686
Abstract
Isfahan Province, Annually, experiences around 650 fatalities and 5,000 injuries due to traffic accidents, with a troubling 20% increase in these figures each year. Alarmingly, half of the traffic-related deaths occur during transport or while receiving medical care. The escalating number of vehicles, coupled with the rapid expansion of transport networks, has led to a significant rise in the frequency and severity of traffic accidents globally, a challenge particularly pronounced in Iran. This phenomenon has resulted in increasing human and economic losses.  In light of these circumstances, the effectiveness of safety policies and preventive measures in Isfahan necessitates the implementation of scientific methods to evaluate interventions aimed at rectifying accident-prone areas, in accordance with international road safety standards. This study endeavors to compare various before-and-after evaluation methodologies. Utilizing the experimental Bayes method, it assesses safety measures implemented at 15 high-accident sites as part of the Safety Improvement Plan for Isfahan Province (e.g. widening the speed limit lane before the round place, installing detector for indicating safety signs, pavement rehabilitation of the speed lane, blocking inappropriate exits and creating parking lots, etc.). The analysis, grounded in experimental observations, aims to provide a robust foundation for future decision-making by transportation managers, planners and engineers. The findings from this assessment reveal that the interventions at the identified sites resulted in a notable 45% reduction in accidents, with a confidence level of 95%. This significant impact validates the appropriateness of the measures undertaken, highlighting their effectiveness in enhancing road safety in the province.
Keywords
Safety
Before-After Study
BAYES Method
Transport Networks
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International Journal of Transportation Engineering
Volume 12, Issue 4 - Serial Number 48
Spring 2025
Pages 2025-2037