Document Type


Publication Date



Increasing the usage of sustainable travel modes requires changes in both environmental and psychological dimensions. A knowledge gap exists concerning the mechanism via which various factors interact to shape travel decision. Gaining such knowledge requires our ability to examine people’s behavioral adjustment in reaction to environmental and psychological changes or interventions.

This project uses COVID-19 as a natural experiment, treating the significant disruption induced by the pandemic as an intervention to study changes in travel behaviors and adoption of different travel choices following the COVID pandemic. This project builds upon a 2020 study conducted by the PI’s. It adopts a mixed-method, longitudinal research plan that takes advantage of the earlier study’s research output about sustainable travel during the 2020 COVID-19 lockdown period.

Findings from this project indicate that people resumed their travel and generally anticipated continuous increase in travel activities by all options (driving, transit, and walking/biking) as society emerges out of the pandemic. The perceived health threat connected to COVID will likely have a persistent influence over people’s future travel choices, especially driving. Some findings indicate that the pandemic experience may make driving less habitual to some people as they started recognizing the feasibility and benefits of using other travel choices, such as walking and biking, to reach some destinations (e.g., parks).

The study shows a clear negative impact from COVID on transit users during the emergency period. The inability to use transit appears to cause significant stress to this group and resulted in people switching to other travel modes. These pandemic experiences may lead to people using less transit in the future. Overall, the environmental factor’s impact on future travel behaviors is weak compared with one’s perceptions, attitudes, and experiences.

These findings suggest that a built- environment approach has limited effectiveness for travel behavior modifications. The greater level of walking or biking in one’s neighborhood produces clear benefits that people can enjoy. These benefits increase people’s likelihood to use more active travel. The experience of reduced driving, however, may not be able to generate a similar level of enjoyment, thus failing to lead to a significant change in driving behavior. Social programs and public campaigns may focus on letting people understand and experience the social and individual benefits associated with less driving.


This is a final report, NITC-RR1504, from the NITC program of TREC at Portland State University, and may be found online at:



Persistent Identifier