To create sustainable and equitable transportation systems, decision-makers need accurate data about how people travel. Yet common survey methods can underrepresent people of color and lower-income communities, leading to unnecessary or misguided infrastructure investments. As major users of eco-friendly transportation, such as public transit, biking, and walking, these communities risk losing resources that could be used to improve transit, pedestrian, and cycling options.

By analyzing transportation survey methodologies and data from Detroit, Seattle, and the Minneapolis–St. Paul region, the project team found clear evidence of this bias and developed actionable recommendations to improve data accuracy and support more sustainable, equitable transportation systems. 

This research team worked with the Southeast Michigan Council of Governments (SEMCOG), the Michigan Department of Transportation (MDOT), and the Twin Cities-area Metropolitan Council to analyze the process and content of current travel surveys and identify sources of bias that may have detrimental economic, environmental, and social effects. They also met with these metropolitan planning organizations to better understand the sampling and processing tools used to improve data quality. Their research found that certain subgroups were either over- or under-represented, depending on their likelihood of responding to travel surveys.

The team also conducted a focused study of the Detroit area in collaboration with SEMCOG, resulting in actionable recommendations, including the development of methodologies designed to capture a sufficient number of perspectives and avoid underrepresentation bias. SEMCOG incorporated these findings into its survey data collection strategies and shared them with a consulting firm working with transportation agencies nationwide.

Beyond opening new lines of research for team members, the project fostered relationships between U-M researchers and with local and regional governments, laying the groundwork for future research and collaboration. The team plans to build on these new connections and continue developing survey methodologies and guidance tools that support equitable and resilient infrastructure systems.

This project received a $10,000 catalyst grant in Fall 2023.

Project team: Atiyya Shaw, PI (Civil and Environmental Engineering); Joe Grengs, Co-I (Urban and Regional Planning); Sunghee Lee, Co-I (Institute for Social Research)