Key risk indicators for accident assessment conditioned on pre-crash vehicle trajectory
•Concept of Key Risk Indicator is developed as surrogate measures of risk exposures.•Two indicators are found to be well-fitting in classifying and identifying risks.•Three risk levels are distinguished by hybridised KRIs with simplified thresholds.•Trajectory data extracted from real-world accident...
Saved in:
| Published in: | Accident analysis and prevention Vol. 117; pp. 346 - 356 |
|---|---|
| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
England
Elsevier Ltd
01-08-2018
|
| Subjects: | |
| Online Access: | Get full text |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | •Concept of Key Risk Indicator is developed as surrogate measures of risk exposures.•Two indicators are found to be well-fitting in classifying and identifying risks.•Three risk levels are distinguished by hybridised KRIs with simplified thresholds.•Trajectory data extracted from real-world accident cases are applied to assess risks.
Accident events are generally unexpected and occur rarely. Pre-accident risk assessment by surrogate indicators is an effective way to identify risk levels and thus boost accident prediction. Herein, the concept of Key Risk Indicator (KRI) is proposed, which assesses risk exposures using hybrid indicators. Seven metrics are shortlisted as the basic indicators in KRI, with evaluation in terms of risk behaviour, risk avoidance, and risk margin. A typical real-world chain-collision accident and its antecedent (pre-crash) road traffic movements are retrieved from surveillance video footage, and a grid remapping method is proposed for data extraction and coordinates transformation. To investigate the feasibility of each indicator in risk assessment, a temporal-spatial case-control is designed. By comparison, Time Integrated Time-to-collision (TIT) performs better in identifying pre-accident risk conditions; while Crash Potential Index (CPI) is helpful in further picking out the severest ones (the near-accident). Based on TIT and CPI, the expressions of KRIs are developed, which enable us to evaluate risk severity with three levels, as well as the likelihood. KRI-based risk assessment also reveals predictive insights about a potential accident, including at-risk vehicles, locations and time. Furthermore, straightforward thresholds are defined flexibly in KRIs, since the impact of different threshold values is found not to be very critical. For better validation, another independent real-world accident sample is examined, and the two results are in close agreement. Hierarchical indicators such as KRIs offer new insights about pre-accident risk exposures, which is helpful for accident assessment and prediction. |
|---|---|
| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0001-4575 1879-2057 |
| DOI: | 10.1016/j.aap.2018.05.007 |