Revisiting TODs: How Subsequent Development Affects the Travel Behavior of Residents in Existing Transit-Oriented Developments

Nathan McNeil, Portland State University



Portland State University has worked with the Portland Metro regional government periodically since 2005 to survey occupants of buildings for which developers had received funding from Metro’s Transit-Oriented Development (TOD) Program. The TOD program, which has a stated goal of funding projects that “stimulate private development of higher-density and mixed-use projects near transit”, engaged PSU to better understand actual transit use, among other factors, of residents in these buildings. In many cases, buildings receiving TOD funding are in neighborhoods undergoing transitions, often through the addition of a light rail line and with updated zoning that encourages dense mixed use development. Many of the surveys were deployed within a year or two of a building opening. Residents’ patterns may change over time, and, as these transit adjacent areas mature into denser, mixed-use neighborhoods, the cumulative effect of changes to land-use and available travel options may influence travel decisions and behavior.

Past research suggests that higher population or job density, along with more retail destinations, tend to lead to fewer auto trips, miles traveled, and more transit use. Less is documented on the effect of longer term residency in TODs on travel choices, or on the maturity of emerging TOD neighborhoods on travel. Revisiting TODs that were surveyed in past years offers the opportunity to understand how several factors affect travel behavior such as the age of the TOD, and changes over time (between the initial survey and the re-survey) in neighborhood residential, job and destination density, and the transportation infrastructure, such as the additional of new transit options. Through this study, we will be able to fill in gaps in how travel behavior changes over the life cycle of a TOD building and maturation of a TOD focused-neighborhood.

This study will select a sample of six to eight TODs that were surveyed between 2005 and 2014 to resurvey. TODs will be selected to attain a set of locations that have experienced considerable change in the surrounding neighborhood. The results will provide insight into how subsequent development may affect the travel behavior of existing residents, along with other factors that influence the relative success of TOD funding in achieving goals of increasing transit trips, and reducing vehicle trips.


Understanding the complex way in which housing style, neighborhood factors, transportation, and the economy combine to influence travel behavior can help cities to maximize the return on their investment in transit-oriented development and supporting transportation and land use policies and investment. For example, knowing that TODs might see a bump in walking and biking activity if a neighborhood reach a certain population or jobs density threshold could encourage consolidated development in key hubs. This hypothetical example could play out in other areas as well, such as the provision of walking of bicycling facilities, the inclusion of frequent service transit routes at certain times of the day, etc.

Project Details

Project Type:
Project Status:
In Progress
End Date:
November 29,2019
UTC Grant Cycle:
NITC 16 Round 2
UTC Funding: