Proactive detection of high collision concentration locations on highways

摘要

In previous research (Chung et al, 2009), the potential of the Continuous Risk Profile (CRP) to proactively detect the systematicdeterioration of freeway safety levels was presented. In this paper this potential is investigated further, and an algorithm isproposed for proactively detecting sites where the collision rate is not sufficiently high to be classified as a high collisionconcentration location but where a systematic deterioration of safety level is observed. The approach proposed compares theweighted CRP across different years and uses the cumulative sum (CUSUM) algorithm to detect the sites where changes incollision rate are observed. The CRPs of the detected sites are then compared for reproducibility. When high reproducibility isobserved, a growth factor is used for sequential hypothesis testing to determine if the collision profiles are increasing over time.Findings from applying the proposed method using empirical data are documented in the paper together with a detaileddescription of the method.