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Journal of Advanced Transportation
Volume 2017 (2017), Article ID 8376572, 9 pages
Research Article

A Novel Surrogate Safety Indicator Based on Constant Initial Acceleration and Reaction Time Assumption

Institute of Highway Engineering, RWTH Aachen University, Aachen, Germany

Correspondence should be addressed to Adrian Fazekas

Received 2 June 2017; Revised 25 October 2017; Accepted 1 November 2017; Published 13 December 2017

Academic Editor: David F. Llorca

Copyright © 2017 Adrian Fazekas et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The development of surrogate safety measures has drawn significant research interest in the field of traffic safety analysis. Innovative data sources such as video-based traffic surveillance systems have made it possible to collect large amounts of microscopic traffic data. By deriving traffic safety indicators such as the Deceleration Rate to Avoid a Crash (DRAC) statements concerning traffic safety over a determined road section can be made. This work presents the derivation of a novel surrogate safety indicator based on a Constant Initial Acceleration and reaction time assumption which considers the interaction between vehicles and describes the traffic safety of a road section. The evaluation is based on a video-based microscopic traffic data collection. To examine the efficiency, the new developed indicator is compared to the original Deceleration Rate to Avoid a Crash (DRAC) and the modified indicator (MDRAC) which includes the reaction time. The results showed that the new indicator is more sensitive in detecting critical situations than the other indicators and in addition describes the conflict situations more realistically.