Transportation Equity

Employment Diversification and Urban Mobility Disparities: A Multi-scale Analysis of U.S. Core-Based Statistical Areas

Wu, Zeyu
Marta Gonzalez
2026

The Economic Complexity Index (ECI), a metric traditionally utilized in international trade to correlate high complexity with lower income inequality, is evaluated here at the subnational level to determine if this relationship persists across diverse urban scales. By adapting the ECI to employment distributions across 121 Core-Based Statistical Areas (CBSAs) in five U.S. states—California, New York, New Mexico, Louisiana, and Mississippi—this study integrates Replica mobility data with American Community Survey socioeconomic indicators. The analysis reveals a significant reversal of...

Strategizing Equitable Transit Evacuations: A Data-driven Reinforcement Learning Approach

Tang, Fang
Wang, Han
Maria Laura Delle Monache
2025

As natural disasters become increasingly frequent, the need for efficient and equitable evacuation planning has become more critical. This paper proposes a data-driven, reinforcement learning (RL)-based framework to optimize public transit operations for bus-based evacuations in transportation networks with an emphasis on improving both efficiency and equity. We model the evacuation problem as a Markov Decision Process (MDP) solved by RL, using real-time transit data from General Transit Feed Specification (GTFS) and transportation networks extracted from OpenStreetMap (OSM). The RL agent...

Public Transit Use in the United States in the Era of COVID-19: Transit Riders’ Travel Behavior in the COVID-19 Impact and Recovery Period

Parker, Madeleine E. G.
Li, Meiqing
Bouzaghrane, Mohamed Amine
Obeid, Hassan
Hayes, Drake
Karen Trapenberg Frick
Daniel Rodriguez
Raja Sengupta
Joan Walker
Daniel Chatman
2021

COVID-19 has upended travel across the world, disrupting commute patterns, mode choices, and public transit systems. In the United States, changes to transit service and reductions in passenger volume due to COVID-19 are lasting longer than originally anticipated. In this paper we examine the impacts of the COVID-19 pandemic on individual travel behavior across the United States. We analyze mobility data from Janurary to December 2020 from a sample drawn from a nationwide smartphone-based panel curated by a private firm, Embee Mobile. We combine this with a survey that we administered to...

Equity Assessment of Transportation Should Incorporate Materials, Supply Chains, and Targeted Mitigation Policies

Greer, Fiona
Bin Thaneya, Ahmad
Apte, Joshua
Jasenka Rakas
Horvath, Arpad
2024

California must build, operate, and maintain transportation infrastructure while ensuring that the health of communities and the planet are not compromised. In addition to vehicleemissions, supply chain inputs and energy use from constructing and maintaining transportation projects (e.g., roads, airports, bridges) result in pollution that contributes to climate change and impacts the health of local communities. Project-specific air and noise pollution can further burden vulnerable populations. By assessing transportation projects using a life-cycle perspective, all relevant emission...

Creating a Data Resource of California Police Stops for Use in Traffic Safety Applications | Safe Transportation Research and Education Center

Julia Griswold
2025

Traffic stops are one of the most common ways in which the American public interacts with police. Although one of the leading reasons given for police traffic stops is a violation of the vehicle code, there is limited and mixed research on the impact of traditional police traffic enforcement on traffic safety outcomes. At present, few large data resources with an appropriate level of detail exist to facilitate investigations of this type. The 2015 Racial and Identity Profiling Act (RIPA) requires all law enforcement agencies in California to collect and submit vehicle (including bicycle)...

Influence of Socioeconomic Factors on Transit Demand During the COVID-19 Pandemic: A Case Study of Bogotá’s BRT System

Caicedo, Juan D.
Joan Walker
Marta Gonzalez
2021

The COVID-19 pandemic restricted most economic and social activities, impacting travel demand for all transportation modes and especially for transit. We hypothesize that the shifts in travel demand varied by socioeconomic status, and we assess the differential impact of COVID-19 in the Bus Rapid Transit (BRT) patronage across various socioeconomic groups in Bogotá. We built a database of frequent transit users with data collected by smartcards in Bogota’s BRT system between January and October 2020. For each user in the database, we labeled their home and work stations. Transactions at...

Collaboration and Equity in Regional Sustainability Planning in California: Challenges in Implementation

Karen Trapenberg Frick
Chapple, Karen
Mattiuzzi, Elizabeth
Zuk, Miriam
2015

Regions across the United States have developed sustainability plans and programs funded through the U.S. Department of Housing and Urban Development’s Sustainable Communities Initiative (SCI). In California, this grant overlapped with a state mandate for regional sustainability planning, SB 375, legislation charging regions with developing long-range sustainability plans to reduce greenhouse gas emissions. Regional agencies lead sustainability planning efforts, yet little is known about how effective and equitable regions are in their engagement with sustainability planning. We examined...

Immigrants and Automobility in New Jersey: The Role of Spatial and Occupational Factors in Commuting to Work

Daniel Chatman
Klein, Nicholas
Lucas, Karen
Blumenberg, Evelyn
Weinberger, Rachel
2011

This chapter presents an overivew and analysis of occupational, spatial, and commuting-mode choices of immigrants to the state of New Jersey.

Why do Immigrants Drive Less? Confirmations, Complications, and New Hypotheses from a Qualitative Study in New Jersey, USA

Daniel Chatman
Klein, Nicholas J.
2013

Recent immigrants to the United States drive autos less than the US-born, with rapid increases in their ownership and use of autos over time, and a persistently lower level of auto use even when controlling for socioeconomic characteristics and time in the US. Quantitative studies have not yet explained these phenomena. Given that population growth in the US is largely dependent on immigration, understanding auto ownership and use among immigrants is important for transportation sustainability. We conducted six focus groups with US residents born in India, the Philippines, and Latin...

Explaining the “Immigrant Effect” on Auto Use: The Influences of Neighborhoods and Preferences

Daniel Chatman
2014

Since immigrants will account for most urban growth in the United States for the foreseeable future, better understanding their travel patterns is a critical task for transportation and land use planners. Immigrants initially travel in personal vehicles far less than the US-born, even when controlling for demographics, but their reliance on autos increases the longer they live in the US. Cultural or habitual differences, followed by assimilation to auto use, could partly explain this pattern; and it may also be partly due to changes in locations and characteristics of home and work...