Development of a Safety Indicator Model Using Braking Behavior at Urban Signalized Four-Leg Intersections

With the growth of the urban population and the resulting increase in the number of vehicles, ensuring safety on urban roads has become inevitable. In this context, the safety assessment of signalized intersections—due to their significant traffic and safety advantages—has become a common approach in traffic management. Signalized intersections are considered critical components of urban service systems. As urban traffic volumes increase, the number of trips rises accordingly, leading to a higher likelihood of conflicts and crashes. This study investigates the geometric and traffic-related factors influencing the frequency of hard braking events at urban signalized intersections, aiming to provide a framework for evaluating the safety index of such locations. This study analyzes the geometric and traffic characteristics of seven urban signalized intersections. Using aerial videography at each site and processing the footage through image analysis software, the number of critical conflicts—based on the hard braking conflict index—was determined. A total of ۹۲,۵۸۶ conflict events related to this safety index were examined. The statistical analysis was performed using a multiple linear regression model. The results indicate that an increase of one unit in traffic volume leads to a ۰.۶% rise in critical conflicts based on the hard braking index. Furthermore, a one km/h increase in average exit speed from intersections is associated with approximately a ۳% increase in critical conflict frequency.

کلیدواژه ها:

Safety Four-Leg Signalized Intersections ، Hard Braking ، performance analysis ، image processing ، Traffic Conflicts