Investigating rural and urban differences in single-vehicle crash severity determinants: a time-of-day analysis using random parameter models

Date

2023

Journal Title

Journal ISSN

Volume Title

Publisher

Kansas State University

Abstract

This study investigates the factors associated with single-vehicle crash injury severity accounting for urban-rural differences and time-of-day variations. We estimate mixed (random-parameter) logit models (with the pseudo direct elasticity values) using five-year (2014 – 2018) crash data for five periods of the day: 12 am – 5 am, 5 am – 9 am, 9 am – 2 pm, 2 pm – 7 pm, and 7 pm – 12 am. Log-likelihood tests confirm the statistical validity of the time-of-day grouping of the crash severity models and the urban-rural separation. Our results indicate variations in effects of factors across time-of-day (e.g., rural roads with ice increase the probability of serious injury for 9 am – 2 pm and 2 pm – 7 pm models and increase fatality probability for the 9 am – 2 pm model; rural road crashes involving oversteering by drivers increases the probability of serious injury for the 12 am – 5 am model, and the 5 am – 9 am models. This variable is found to decrease the probability of serious injury for the 9 am – 2 pm model and for the 7 pm – 12 am model; female drivers in rural crash models are found to be less prone to fatality except for the 12 am to 5 am model, and the effect of this variable is found as random in the 5 am – 9 am, 9 am – 2 pm and 2 pm – 7 pm models. The findings of this research can be applied to improve state-specific Crash Modification Factors (CMFs) and Safety Performance Functions (SPFs).

Description

Keywords

Single vehicle crashes, Injury-severity, Time of day, Temporal instability, Logit model, SPF and CMF

Graduation Month

December

Degree

Master of Science

Department

Department of Civil Engineering

Major Professor

Christopher A. Jones

Date

Type

Report

Citation