The surrogate safety assessment model (SSAM) is a tool to identity traffic conflicts by tracking and processing space-time diagram of simulated vehicles’ trajectories which are generated by a micro-simulation model. In this study simulated conflicts of the SSAM were used to pre-evaluate the safety impact of signal timing optimization plan which is usually applied to improve traffic conditions at mixed-traffic signalized intersections. A typical signalized intersection in Hanoi city where motorcycles are used prevalently was selected and a micro-simulation model using VISSIM according to the field traffic data was developed to obtain vehicles’ trajectories. And then the output file of vehicles’ trajectories was analyzed by the SSAM to identify simulated conflicts, including time-to-collision (TTC) and the numbers of conflicts which consist of rear-end, crossing and lane-change conflicts. The analysis results indicated that compared to initial signal timings the estimated number of conflicts was reduced by 14.6% and improved the average value of TTC (15.4%). This means that the timing optimization plan not only improves traffic conditions but also improves traffic safety in comparison to the existing timing plan. Moreover, the use of VISSIM, along with the SSAM at intersections is a fast way to examine the safety impact of proposed solutions, as well as contribute to the improvement of safety in mixed traffic flow.
Safety Impact of Timing Optimization at Mixed-Traffic Intersections Based on Simulated Conflicts: A Case Study of Hanoi, Vietnam
2019-09-01
3356070 byte
Conference paper
Electronic Resource
English
Estimating the Safety of Unsignalized Intersections Using Traffic Conflicts
British Library Conference Proceedings | 1997
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