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Exposing the Dangers of Distance: Mining Crash Narratives to Explore Why Pedestrians Face Severe Injury and Death Far From Home

Project Description

Pedestrian fatalities in the United States have risen by 83% over the past 15 years, with much of the increase occurring on multilane suburban arterials. In Tennessee, deaths nearly tripled between 2009 and 2022, with studies linking crashes to high-speed midblock locations lacking pedestrian infrastructure. Spatial analysis shows pedestrians are being struck farther from home: in 2014 the median distance between residence and crash site was 1.5 miles, compared to four miles by 2023, while the share of crashes within one mile of home fell from 46% to 30%. Relative to city centers, crash locations remain stable, but the distance between city centers and pedestrian residences has grown, indicating that more crashes involve individuals living farther from urban cores. These shifts suggest pedestrians are traveling into distant, high-risk environments, raising essential questions about why they are walking in such areas and what broader urban trends contribute to this exposure. This study applies a hybrid methodology combining structured crash records with insights from unstructured police narratives from Tennessee’s Integrated Traffic Analysis Network (2014–2024). A home-based approach links pedestrian and driver addresses with U.S. Census block group characteristics, including income levels, vehicle ownership, education, commuting modes, and housing density, to better understand who is involved in these crashes. Artificial intelligence is used to analyze crash narratives for trip purposes such as traveling to grocery stores, bus stops, schools, or workplaces, offering contextual information not captured in standard crash reports. Specifically, this study will locally deploy an open-source large language model (e.g., Gemma or Grok) to serve as a traffic crash analysis agent, capable of addressing questions that help uncover the motivations behind pedestrian trips based on police crash narratives. By conducting all processing locally, this approach ensures the privacy of both pedestrians and drivers is preserved. Together, these methods distinguish between near-home and far-from-home crashes, highlight populations more frequently affected, and examine the role of broader urban development patterns. The findings will support city- and neighborhood-level safety strategies, helping target interventions on hazardous arterials and informing policies for improved safety.

Outputs

The study seeks to develop an agentic AI system, built on an open-source large language model and hosted locally to ensure the privacy of drivers and pedestrians. This system is designed to extract latent information about pedestrian trips and other crash details from narrative reports. This information is often too extensive for human analysts to process and, therefore, typically remains unnoticed or unused in traffic crash analyses. Over the course of the project, the system will be fine-tuned to more accurately capture and extract relevant details from crash narratives, further enhancing the quality and depth of the analysis.

 

Another key output of the study is a classification system for pedestrian crashes that uses both pedestrian home locations and city centers as reference points. This system categorizes crashes according to the surrounding urban structure, distinguishing among core city center crashes, inward crashes, peripheral (suburban) crashes linked to shorter travel distances, and peripheral crashes associated with longer travel distances.

 

Another output of the project is a set of descriptive and econometric analyses that enhance understanding of the information extracted through AI techniques. These analyses will merge crash narrative data with census records, travel distances, and other crash details, producing an integrated framework that combines AI-derived insights with socioeconomic and spatial data to provide a more comprehensive understanding of pedestrian crashes. Finally, guided by a thorough analysis of associated risk factors and grounded in safety principles, the study intends to offer a set of effective countermeasures at the city- and neighborhood-level.

 

In addition to methodological contributions and the final report, this study will result in at least one article published in a peer-reviewed journal.

Outcomes/Impacts

This project will generate new knowledge, tools, and methods that directly inform the design and implementation of safer transportation systems for pedestrians. By integrating structured crash data with narrative-based insights, the study moves beyond traditional analyses that focus solely on crash frequency and severity. Instead, it identifies why pedestrians are traveling in high-risk environments, what purposes their trips serve, and how broader shifts in urban form and demographics influence crash exposure. These insights create an evidence base that can guide more targeted, context-specific safety strategies at both the neighborhood and city levels.

 

A central output of this work is the development of an AI-driven classification and analysis system for crash narratives. Hosted locally to protect sensitive information, this system will allow researchers, agencies, and practitioners to systematically extract latent information from narrative records (e.g. trip purposes, environmental conditions, or contextual circumstances) that is rarely accessible through conventional crash databases. This tool represents a significant methodological advancement for transportation safety research. Automating narrative analysis enables large-scale, reproducible assessments that would otherwise be infeasible for human analysts. Over time, this system can be adapted for other states or integrated into federal crash reporting practices, potentially influencing how data is collected, processed, and used nationwide.

 

Another significant contribution is the home-based classification framework for pedestrian crashes, which uses both residence locations and urban structure (city centers, suburban peripheries, etc.) to categorize crash contexts. This system will allow practitioners to distinguish between near-home and far-from-home crashes, and to identify patterns linked to suburbanization, commuting, or limited access to essential services. Such insights can directly inform local planning decisions, from where to prioritize crosswalks and traffic calming to how transit stops and pedestrian access routes are designed.

 

In terms of policy and practice, the findings will provide actionable recommendations aligned with safety principles, focusing on arterials where pedestrians are most at risk. Results can inform the prioritization of roadway redesign projects, the placement of pedestrian infrastructure (e.g., midblock crossings, lighting, refuge islands), and targeted enforcement or education strategies. By highlighting where and why crashes occur farther from home, the study also equips agencies to anticipate and mitigate risks associated with population shifts, suburban expansion, and changes in travel behavior.

 

The anticipated impacts extend across multiple dimensions of the transportation system. In safety terms, the outputs support reductions in severe and fatal pedestrian crashes, particularly in suburban contexts where risks are escalating. Beyond direct infrastructure applications, this research has the potential to shape state and federal policy discussions around pedestrian safety, data collection practices, and roadway design standards, ultimately contributing to a safer, more resilient transportation system for all users. Lastly, the peer-reviewed journal publication will ensure the research findings are rigorously validated, widely disseminated, and positioned to influence future transportation safety research and practice.

Dates

12/1/2025 to 11/30/2026

 

Universities

University of Tennesee Knoxville

 

Principal Investigator

Christopher Cherry

cherry@utk.edu

https://orcid.org/0000-0002-8835-4617

 

Saurav Parajuli

parajuli@utk.edu

https://orcid.org/0000-0003-4534-2832

 

Project Partners

None

 

Research Project Funding

Federal: $108,792

Non-Federal: $71,561

 

Contract Number

69A3552348336

 

Project Number

25UTK01

 

Research Priority

Promoting Safety

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