A hybrid of regularization method and generalized path analysis: modeling single-vehicle run-off-road crashes in a cross-sectional study

Fatemeh Jahanjoo, Mohammad Asghari-Jafarabadi, Homayoun Sadeghi-Bazargani

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background: Determining risk factors of single-vehicle run-off-road (SV-ROR) crashes, as a significant number of all the single-vehicle crashes and all the fatalities, may provide infrastructure for quicker and more effective safety measures to explore the influencing and moderating variables in SV-ROR. Therefore, this paper emphasizes utilizing a hybrid of regularization method and generalized path analysis for studying SV-ROR crashes to identify variables influencing their happening and severity. Methods: This cross-sectional study investigated 724 highway SV-ROR crashes from 2015 to 2016. To drive the key variables influencing SV-ROR crashes Ridge, Least Absolute Shrinkage and Selection Operator (Lasso), and Elastic net regularization methods were implemented. The goodness of fit of utilized methods in a testing sample was assessed using the deviance and deviance ratio. A hybrid of Lasso regression (LR) and generalized path analysis (gPath) was used to detect the cause and mediators of SV-ROR crashes. Results: Findings indicated that the final modified model fitted the data accurately with X32 = 16.09, P <.001, X2 / degrees of freedom = 5.36 > 5, CFI =.94 >.9, TLI =.71 <.9, RMSEA = 1.00 >.08 (90% CI = (.06 to.15)). Also, the presence of passenger (odds ratio (OR) = 2.31, 95% CI = (1.73 to 3.06)), collision type (OR = 1.21, 95% CI = (1.07 to 1.37)), driver misconduct (OR = 1.54, 95% CI = (1.32 to 1.79)) and vehicle age (OR = 2.08, 95% CI = (1.77 to 2.46)) were significant cause of fatality outcome. The proposed causal model identified collision type and driver misconduct as mediators. Conclusions: The proposed HLR-gPath model can be considered a useful theoretical structure to describe how the presence of passenger, collision type, driver misconduct, and vehicle age can both predict and mediate fatality among SV-ROR crashes. While notable progress has been made in implementing road safety measures, it is essential to emphasize that operative preventative measures still remain the most effective approach for reducing the burden of crashes, considering the critical components identified in this study.

Original languageEnglish
Article number221
Number of pages14
JournalBMC Medical Research Methodology
Volume23
Issue number1
DOIs
Publication statusPublished - Dec 2023

Keywords

  • Accident
  • Causal effect
  • Elastic net regression
  • Generalized path analysis
  • Lasso regression
  • Ridge regression
  • Traffic accidents

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