Date of Award

Spring 2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Civil & Environmental Engineering

Program/Concentration

Civil and Environmental Engineering

Committee Director

Kun Xie

Committee Member

Mecit Cetin

Committee Member

Hong Yang

Committee Member

Qing Tang

Abstract

This dissertation aims to understand how disruptive events —particularly the COVID-19 pandemic—affect driving behaviors, transportation safety and equity by leveraging advanced statistical modeling techniques and data from Virginia. This research pursues three overarching objectives. First, it employs multigroup structural equation modeling (SEM) to uncover the complex interrelationships among risky driving behaviors, injury severity, and pandemic-related factors, delineating the mechanisms through which COVID-19 has impacted crash outcomes via changing risky driving behaviors. Second, it leverages hidden Markov models to trace shifts in safety states over the pre-, during-, and post-pandemic periods, determining whether and when safety conditions return to pre-pandemic norms. Lastly, it applies a difference-in-differences (DID) approach to explore whether disadvantaged populations and communities have been disproportionately affected by pandemic-related changes in crash outcomes, addressing vital issues of transportation safety equity.

The results suggest that aggressiveness and inattentiveness of drivers increased significantly after the outbreak of COVID-19, leading to a higher likelihood of severe crashes. Safety states related to risky driving behaviors and the proportion of severe crashes were at lower-risk levels pre-pandemic from 2016 to 2019, then escalated to the highest-risk levels during the pandemic in 2020 and remained at higher-risk levels in 2021, 2022 and 2023. By 2024, safety states have returned to lower-risk levels similar to those inferred in the pre-pandemic period. Further, disadvantaged areas faced higher proportions of both all crashes and severe crashes compared to non-disadvantaged areas, and the pandemic intensified the disparities by further increasing proportions of both total crashes and severe crashes in disadvantaged areas in 2020. In post-pandemic from 2021 to 2024, there was still a significant increase in the proportions of all crashes in disadvantaged areas.

This study helps understanding how a disruptive event change driving behaviors and safety outcomes, provides temporal perspective on how safety states shift across different phases of a disruptive event, and contribute to equity-centered transportation research and underscores the need for inclusive safety policies. This dissertation offers novel analytical approaches and actionable insights that can inform policy interventions and targeted strategies for safer, more equitable transportation systems under impacts of disruptive events.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

DOI

10.25777/kknm-b588

ISBN

9798280751699

Download

Share

COinS