Temporal instability of factors affecting injury severity in single-vehicle crashes on rural highways

ABSTRACT

To study the time-of-day variations and temporal stabilities of factors influencing single-vehicle crashes on rural highways, random parameters logit models with heterogeneity in means and variances under different time periods of the day and from year to year were estimated to identify significant factors. The potential crash-influencing factors in drivers, vehicles, roads, and the environment were analyzed to dissect the correlation and variability between the influencing factors and crash injury severity. Likelihood ratio tests were conducted to assess the transferability of model estimation results from different times of the day and from year to year. The results showed that the effect of factors that determine injury severity varied significantly across time-of-day/time-period combinations. Overall temporal instability was observed in the study. However, several explanatory variables showed temporally stable effects in terms of their impact on resulting injury severities. Such as male, driver age (<30), truck, non-dry road surface, and visibility (100–200 m).

KEYWORDS:

• Traffic safety
• rural single-vehicle crashes
• random parameters logit model
• injury severity
• heterogeneity in means and variances

Acknowledgments

The authors appreciate the support of the Shandong Department of Transportation (SDOT), the Zibo Department of Transportation (ZDOT), and the Center for Accident Research in Zibo (CARZ).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to security and privacy issues.

Additional information

Funding

This research was jointly supported by the National Natural Science Foundation of China [Grant No. 52272343], Open Project of Key Laboratory of Road Traffic Safety of the Ministry of Public Security [Grant No. 2023ZDSYSKFKT14] and University and Urban Integration Development Plan Project of Zhangdian District [Grant No.2022JS002].