"I’d like accessibility analysis to help us shape the future”: Transportation practitioners and accessibility measurement

By Dana Rowangould, Alex Karner, Kaylyn Levine & Louis Alcorn

Transportation affects peoples’ day-to-day lives in myriad ways, including the ability to get where they need to go, the economic wellbeing of individuals and communities, physical and mental health, and the health of the local environment and planet. Transportation agencies are becoming increasingly interested in measuring accessibility, or the ease with which people can reach desired destinations. In part, the concept is attractive because it reflects the primary purpose of a transportation system—to connect people to the opportunities they value. Using accessibility measures to evaluate the performance of transportation plans and projects better positions them to support contemporary transportation mobility options including walking and biking, reducing the distances that people travel, and reducing greenhouse gas emissions.

Academic researchers have identified a wide range of accessibility measures that vary widely in terms of how they are estimated, their interpretability, data requirements, and their relevance to different areas of transportation planning and decision-making. At the same time, new data and tools that facilitate and improve accessibility measurement are proliferating. Despite the promise of access measures, the landscape is vast and expanding, which can be difficult for practitioners to navigate. In fact, the use of accessibility in practice is relatively limited, with only a small share of U.S. transportation agencies using these measures.

In this paper, we draw from 45 interviews with transportation professionals and a follow-up survey to determine how U.S. transportation practitioners currently use accessibility measures, barriers to accessibility measurement, and opportunities to use accessibility measures moving forward. We find that for agencies that use accessibility measures, the lion’s share of accessibility applications in practice employs simple measures that are relatively straightforward to estimate and easier to interpret than more complex measures. We do not find widespread use of more complex and technically demanding measures, although some agencies report using them to gain additional insight about transportation system performance.

Our results point to a wide range of technical capacities and accessibility applications across agencies. Practitioners determining whether and how to measure accessibility weigh many factors, including the ease of interpreting measures as well as the resources required to estimate them. In some cases, accessibility is seen as just one performance measure among many. In others, analysts use accessibility to highlight a fundamental objective of the transportation system, the connection between transportation and land use, or the benefits of projects that support nonmotorized travel.

Importantly, many practitioners expressed a desire to expand their use of accessibility measures but described barriers to doing so. Resource constraints, limitations in agency knowledge, available data, and the ways that accessibility has been conceptualized and interpreted have led to gaps between how accessibility could be used and how it has been used in practice. Overcoming these barriers would require targeted staff hiring and training, expanding the use of relatively simple measures, working with available or readily attainable datasets, and using available guidance documents. While the findings reported here are based on U.S. data, they echo many of the challenges and opportunities posed by accessibility measurement that have been reported in the European context, including institutional and informational barriers to applying accessibility in practice as well as a need to strengthen the ways that accessibility measures are communicated.

We note that accessibility measurement has typically focused on quantitative measures based on available data, which hinders our ability to apply the concept of accessibility broadly. Understanding people’s perceived accessibility, tangible and intangible barriers to access, and unmet travel needs is needed in future research. At the same time, applying the concept of accessibility and expanding the notion of accessibility to capture peoples’ experiences with transportation systems both present an opportunity to advance the use of accessibility in practice to improve the design of transportation systems.

Our findings provide a snapshot of accessibility measurement practice in the U.S. and point to the need for resources and guidance to increase practitioners’ knowledge and understanding of accessibility measurement. These findings were part of a body of research used to inform new guidance on the use of accessibility measurement in practice.

Article Details
“I’d Like Accessibility Analysis to Help Us Shape the Future”: Transportation Practitioners and Accessibility Measurement
Authors: Dana Rowangould, Alex Karner, Kaylyn Levine & Louis Alcorn
First Published: May 11, 2024
DOI: 10.1177/03611981241239653
Transportation Research Record: Journal of the Transportation Research Board

About the Authors

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Louis G. Alcorn is a Lead Consultant in the Transit/Rail Finance group at WSP USA. He leads financial planning for transportation projects around the country and serves as the deputy finance lead of the Interstate Bridge Replacement (IBR) Program megaproject, which will provide an improved multimodal connection between Portland, Oregon and Vancouver, Washington. Prior to joining WSP, Louis worked in capital finance and transit planning at the San Francisco Municipal Transportation Agency (SFMTA) and Capital Metro in Austin, respectively. He obtained a MS in Transportation Engineering and a MS in Community and Regional Planning from the University of Texas at Austin where his research interests spanned multimodal transportation planning, governance, operations, accessibility, and social equity analysis, with a particular focus on the informal transit in the Global South.

Dr. Levine is an Assistant Professor in the Community and Regional Planning program housed within the Department of Geography, Planning, and Environment at East Carolina University. She is a transportation planning scholar with published research on how first and last mile access to transit and accessibility for disabled people. Her work focuses on the equity implications of active and public transportation planning decisions using a mobility justice lens. Dr. Levine’s research uses mixed-methods and community engagement to understand transportation needs and experiences.

Dana Rowangould is an Assistant Professor in the Department of Civil and Environmental Engineering at the University of Vermont. Drawing from the fields of engineering, economics, and the social sciences, Dr. Rowangould’s research includes rural travel behavior, transportation equity and justice, transportation and land use planning, energy use and air quality, and multi-modal transportation. Her work is motivated by a desire to improve transportation systems so they better serve people, particularly those whose ability to travel is constrained by their individual needs and transportation options.

Alex Karner is an associate professor of community and regional planning at The University of Texas at Austin. With a background in civil and environmental engineering, Dr. Karner's research focuses on transportation planning, mobility justice, and sustainability. He regularly collaborates with community groups and legal advocates to identify and address priority unmet needs for underserved groups. His innovative approaches integrate critical elements including race, gender, and personal experiences into transportation planning research and modeling. His work has been supported by various federal agencies and foundations.