Doctoral Dissertations
Date of Award
8-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Major
Civil Engineering
Major Professor
Christopher R. Cherry
Committee Members
Kevin Heaslip, Russel Zaretzki, Jonathan D. Hall
Abstract
In this dissertation, I examine the sharp rise in pedestrian fatalities in the United States and globally. In the U.S., pedestrian deaths increased by over 80% between 2009 and 2022. I investigate how factors such as roadway design, trip purposes, socio-economic conditions, and vehicle design trends have contributed to this increase. I also introduce a new method for understanding how pedestrians perceive safety in low-income South Asian cities, which carry a significant share of the global pedestrian fatality burden.
I use Tennessee as the primary case study due to its nearly threefold increase in pedestrian fatalities since 2009, closely reflecting national trends. My goal is to identify how road, vehicle, and pedestrian characteristics influence the likelihood of fatal outcomes in crashes. I take a mixed-methods approach across three main chapters using state police crash data. In the first chapter, I analyze the relationship between roadway design and fatal pedestrian outcomes. In the second, I explore spatial and socio-economic disparities, supported by crash narratives processed with artificial intelligence (AI). In the third, I assess how vehicle characteristics—specifically height, weight, and age—interact with posted speed limits to influence injury severity. I also include a perception-based survey from Kathmandu, Nepal, to understand how pedestrians in low-income urban areas perceive safety in the absence of reliable crash data.
My findings show that fatal pedestrian crashes are more likely on high-speed urban arterials, in non-intersection areas, and where pedestrian infrastructure is lacking. Risk has grown in suburban areas, especially for people walking for essential needs. A key insight is that urbanizing suburban spaces have shifted walking behavior faster than infrastructure has adapted. While larger vehicles increase injury odds at low speeds, changes in the vehicle fleet alone do not fully explain the rise in fatalities.
Survey responses from South Asia highlight the importance of basic infrastructure in shaping pedestrians’ sense of safety, especially along multilane or narrow roads.
I conclude that rising fatalities are linked to high-speed roads, evolving built environments, and socio-demographic vulnerabilities. While long-term progress depends on vehicle design and walking behavior, immediate improvements require speed management and baseline infrastructure.
Recommended Citation
Parajuli, Saurav, "Confronting the Pedestrian Safety Crisis: Exploring Injury Severity and Underlying Mechanisms. " PhD diss., University of Tennessee, 2025.
https://trace.tennessee.edu/utk_graddiss/12754