Intersection Safety Assessment Using Video-Based Traffic Conflict Analysis: The Case Study of Thailand

Nopadon Kronprasert,Paramet Luathep,Chomphunut Sutheerakul,Thaned Satiennam

doi:10.3390/su132212722

Nopadon Kronprasert, Paramet Luathep + Show 2 more

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https://doi.org/10.3390/su132212722

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Abstract

In the road transport network, intersections are among the most critical locations leading to a risk of death and serious injury. The traditional methods to assess the safety of intersections are based on statistical analyses that require crash data. However, such data may be under-reported and omit important crash-related factors. The conventional approaches, therefore, are not easily applied to making comparisons of intersection designs under different road classifications. This study developed a risk-based approach that incorporates video-based traffic conflict analysis to investigate vehicle conflicts under mixed traffic conditions including motorcycles and cars in Thailand. The study applied such conflict data to assess the risk of intersections in terms of time-to-collision and conflict speed. Five functional classes of intersections were investigated, including local-road/local-road, local-road/collector, collector/arterial, collector/collector, and arterial/arterial intersections. The results showed that intersection classes, characteristics, and control affect the behavior of motorists and the safety of intersections. The results found that the low-order intersections with stop/no control are high risks due to the short time-to-collision of motorcycle-related conflicts. They generate frequent conflicts with low chance of injury. The high-order intersections with signal control are high risks due to high conflicting speeds of motorcycle–car conflicts. They generate few conflicts but at a high chance of injury. The study presents the applicability of video-based traffic conflict analysis for systematically estimating the crash risk of intersections. The risk-based approach can be deemed as a supplement indicator in addition to limited crash data to evaluate the safety of intersections. However, future research is needed to explore the potential of other road infrastructure under different circumstances.

Highlights

Intersections are among the most critical locations in the road transport network resulting in a risk of death and serious injury [1]
The results are presented in tworisk reThis study appliedintersection video-basedsites traffic conflict analysis to investigate the conflict of vehicles at different intersection sites
The number of traffic conflicts were recorded from 7:00 a.m. to 7:00 p.m. (12 h)

Summary

Introduction

Intersections are among the most critical locations in the road transport network resulting in a risk of death and serious injury [1]. Intersection-related crashes account for approximately 20–45% of all reported crashes in both developed and developing countries, such as the United States, Norway, Japan, Singapore, and Thailand [2,3,4,5,6]. The factors contributing to intersection-related crashes are diverse and complex. Many factors, such as intersection types, control, and geometry, have different impacts on crash types and their frequency and severity [7]. Four-legged intersections have up to four times the number of crashes as T-intersections. Signalized intersections have higher percentages of rear-end collisions than stop-controlled intersections.

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