Modeling Accident Duration and Its Mitigation Strategies on South Korean Freeway Systems

Understanding the relationship between the characteristics of an accident and its duration is crucial for efficient response to and timely clearance of an accident, which can minimize traffic delays and congestion on the freeway. Although about 3,000 traffic accidents occur annually on South Korean freeways, only limited studies have been conducted that comprehensively model traffic accidents, including characteristic attributes such as accident duration. The objective of this study is to analyze the critical factors that affect accident duration by means of an accelerated failure time (AFT) metric model and to develop strategic plans and mitigation measures for reducing accident duration on South Korean freeway systems. In total, 2,940 accident data sets, spanning one year (2004), are used. On the basis of the log logistic AFT metric model and survival analysis, the paper suggests some strategic plans and mitigation measures to reduce accident duration on freeway systems in South Korea. In particular, it is hypothesized that, for accidents that occur at night or in a work zone area or are taxi related, the accident duration can be reduced by, among other measures, adding more roadside facilities, employing better freeway management strategies, changing taxi-related policies, or using any combination of those measures. Overall, analytical modeling of traffic accidents and their characteristic attributes, as demonstrated in this paper, should be used routinely as an aid in the strategic planning and formulation of mitigation measures for reducing accident duration on Korean freeway systems.