University of Michigan Transportation Security Index Survey Data and Project Reports (2022 and 2024)

This project, titled “Developing a 3-itemTransportation Security Index,” developed and validated a 3-item Transportation Security Index (TSI), a measure designed to directly capture the experience of transportation insecurity at the individual level regardless of mode of transit or geography. Planners, researchers, and policy makers needed an even shorter form than the existing validated 16-item long form (TSI-16) and 6-item short form (TSI-6). To that end, we used nationally representative survey data collected in 2022 to first identify a 3-item short form (TSI-3). We then replicated and validated this short form by fielding an original nationally representative survey in 2024. To validate the short form, we used the 2024 data to assess the level of agreement between the TSI-3 and the TSI-6. We also compared the predictive power of each of these TSI forms by examining how they were associated with key outcomes, including physical and mental health. The study was determined to be exempt by UM IRB (protocol number HUM00096242)