Microscopic evaluation of traffic safety at signal coordinated intersections: A before-after study
Guopeng Zhang1, Wenbo Fan1,2, Teng Meng1
1a School of Transportation and Logistics , Southwest Jiaotong University , Chengdu , China.
Traffic Injury Prevention
|December 14, 2018
Summary
Signal coordination can increase intersection crashes, especially rear-end and sideswipe types during off-peak hours. This traffic signal strategy disperses crash locations but heightens risks at intersection approaches.
Area of Science:
- Traffic Engineering
- Transportation Safety
- Statistical Modeling
Background:
- Signal coordination is widely used to improve traffic flow.
- However, its impact on traffic safety at signalized intersections is not fully understood.
- Evaluating safety implications is crucial for optimizing traffic management.
Purpose of the Study:
- To assess the safety impacts of signal coordination on signalized intersections.
- To provide a scientific basis for improving signal control strategies from a safety perspective.
Main Methods:
- Kernel regression model used to evaluate intersection safety before and after signal coordination implementation.
- Analysis of nonlinear relationships between crash frequency and spatial location.
- Examination of crash spatial distribution discrepancies under coordination vs. noncoordination.
Main Results:
- Crash distribution on arterials becomes more dispersed with signal coordination.
- Intersection approach crash frequency increases with signal coordination during nonpeak hours.
- Increased crashes observed for rear-end and sideswipe types, low-speed intersections, and both injury and property damage-only crashes.
Conclusions:
- Signal coordination presents safety concerns alongside its operational benefits.
- Traffic safety evaluations are essential when designing or improving signal control systems.
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