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Severity analysis of single-vehicle left and right run-off-road crashes using a random parameter ordered logit model
Sunday Okafor1,2, Emmanuel Kofi Adanu2, Abhay Lidbe2
1Department of Civil, Construction, and Environmental Engineering, The University of Alabama, Tuscaloosa, Alabama.
Traffic Injury Prevention
|February 9, 2023
Summary
Left run-off-road (L-ROR) crashes are more severe than right run-off-road (R-ROR) crashes. Factors like male drivers, DUI, and road conditions influence severity in both types of single-vehicle (SV) run-off-road incidents.
Area of Science:
- Road Safety
- Traffic Engineering
- Accident Analysis
Background:
- Single-vehicle (SV) run-off-road (ROR) crashes are a significant cause of severe injuries and fatalities.
- Crash severity varies based on the direction of the run-off-road event (left or right).
Purpose of the Study:
- To investigate factors contributing to the crash severities of right run-off-road (R-ROR) and left run-off-road (L-ROR) SV crashes.
- To differentiate contributing factors for R-ROR and L-ROR crash severities.
Main Methods:
- Utilized SV crash data from Charlotte, North Carolina (2014-2017).
- Developed two random parameter ordered logit (RPOL) models to analyze R-ROR and L-ROR crash severities.
- Quantified variable impacts using direct pseudo-elasticities.
Main Results:
- Male drivers, Driving Under Influence (DUI), motorcycles, and dry roads significantly contributed to both R-ROR and L-ROR crash severities.
- R-ROR severity increased with speeding, reckless driving, fewer lanes (1-2), and older drivers.
- L-ROR severity increased with phone distraction, centerline/median crossing, more lanes (3-4), rain, and dark unlighted roads.
Conclusions:
- Left run-off-road (L-ROR) SV crashes are inferred to be more likely to result in severe outcomes compared to R-ROR crashes.
- Provides insights into contextual factors influencing ROR SV crash severity for developing targeted countermeasures.
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