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The Role of Urban Form, and Demographics, and Disadvantaged Communities in Pedestrian and Bicycle Safety

Project Description

One of the core objectives of the National Roadway Safety Strategy (NRSS) is to enable safety for all road users, especially vulnerable road users (VRU) that include pedestrians and bicyclists. Meanwhile, the United States Department of Transportation (USDOT) is taking initiatives to understand and, where appropriate, resolve disproportionate safety impacts of crashes on historically disadvantaged communities (DACs). In this regard, the USDOT released data on such communities at the census tract level through the Justice40 initiative and aimed to address transportation equity issues. Specifically, six comprehensive indicators identify DACs based on economy, environment, equity, health, resilience, and transportation.


A fundamental research question to be answered is whether the DAC indicators, urban form (e.g., density, land use mix, alternative mode infrastructure), and demographics (race or gender) are correlated with higher levels of pedestrian and bicyclist crashes at the national and regional levels. All three are closely related, e.g., the urban form can lead to segregation and concentration of DACs with limited access to resources such as safe infrastructure, services, and economic opportunities. Additionally, when analyzing pedestrian and bicycle safety, the study will investigate the extent of inequities regarding transportation safety and the presence of spatial heterogeneity and explore the safe systems interventions to effectively address vulnerable road user safety.


The study will create a unique large-scale dataset by combining ten years of fatal crash data with demographic information and DAC indicators for the 72,000-plus census tracts in the US. The data is proposed to be analyzed using descriptives to understand data characteristics and distributions, time-series analysis to examine pedestrian and bicycle fatalities over time, and Geographically Weighted Regression (GWR) to account for the spatial variations in relationships and enable insights into the spatially varying correlates of safety outcomes.


1) A key outcome of this project is a Technical Report describing the creation of a unique large-scale pedestrian and bicycle safety database. The report will examine trends and dynamics over ten years, reveal spatial and temporal changes in safety outcomes, and uncover localized relationships, focusing on urban forms, demographics, and community disadvantages.


2) New pedestrian and bicycle safety processes are to include: i) Integrated Spatial and Temporal Data and Analysis-guidance will be provided for creating pedestrian and bicycle safety databases and analyzing them at the local or regional levels. ii) Urban Form and Safety-establishing a process to examine urban design strategies, such as improvements needed in road configurations, land use patterns, and built environment features. iii) Demographic Analysis- systematically examining safety disparities across demographic groups and how to address them. iv) The predictive models will proactively identify areas at higher crash risk and guide the allocation of resources for safety improvements.


Overall, the research will create and analyze a large-scale safety database, emphasizing understanding of disadvantaged communities, urban form and demographic factors and generating new processes for examining and addressing pedestrian and bicycle safety challenges. These processes will contribute to informed decision-making, targeted interventions, and develop more effective policies to enhance safety outcomes in disadvantaged communities.


1) Output: The study will create new knowledge about pedestrian and bicycle safety disadvantaged communities in different contexts characterized by urban forms/infrastructure variations and demographics.


2) Anticipated changes to the transportation system include implementing effective safe systems interventions at a localized level and assisting policymakers in allocating resources to improve disadvantaged communities on a priority basis.


3) The study informs policy decisions related to equity and promoting social justice in transportation planning and policymaking. The role of safe systems initiatives will be explicitly considered in communities that can benefit most from such interventions. The policy framework will include targeted interventions based on localized safety analysis in disadvantaged communities. The research will guide transportation agencies and policymakers in implementing equitable and targeted safety interventions and infrastructure improvements in these communities, ensuring that safety interventions are prioritized where they are most needed. The research will lead to more informed and equitable resource allocation that can reduce disparities and improve safety outcomes.


4) Additionally, the project will train students in research on equity and disparities, and the insights gained from the research can inform education and training programs targeted at disadvantaged communities. Overall, by addressing pedestrian and bicycle safety challenges in disadvantaged communities, the research will contribute to more equitable and inclusive environments that prioritize the safety and well-being of all residents.


06/01/2023 to 05/31/2024


University of Tennessee-Knoxville

Principal Investigator

Asad Khattak

University of Tennessee-Knoxville
ORCID: 0000-0002-0790-7794

Daniel Rodriguez 

University of California Berkeley
ORCID: 0000-0001-6550-5518

Christopher Cherry
University of Tennessee-Knoxville
ORCID: 0000-0002-8835-4617

Research Project Funding

Federal: $94,868

Non-Federal: $25,731

Contract Number


Project Number


Research Priority

Promoting Safety

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