A tree-structured crash surrogate measure for freeways

Publication Type:
Journal Article
Accident Analysis and Prevention, 2015, 77 pp. 137 - 148
Issue Date:
Filename Description Size
1-s2.0-S000145751500041X-main.pdfPublished Version1.48 MB
Adobe PDF
Full metadata record
© 2015 Elsevier Ltd. All rights reserved. In this paper, we propose a novel methodology to define and estimate a surrogate measure. By imposing a hypothetical disturbance to the leading vehicle, the following vehicle's action is represented as a probabilistic causal model. After that, a tree is built to describe the eight possible conflict types under the model. The surrogate measure, named Aggregated Crash Index (ACI), is thus proposed to measure the crash risk. This index reflects the accommodability of freeway traffic state to a traffic disturbance. We further apply this measure to evaluate the crash risks in a freeway section of Pacific Motorway, Australia. The results show that the proposed indicator outperforms the three traditional crash surrogate measures (i.e., Time to Collision, Proportion of Stopping Distance, and Crash Potential Index) in representing rear-end crash risks. The applications of this measure are also discussed.
Please use this identifier to cite or link to this item: