New research from Portland State University's Transportation Research and Education Center (TREC) shows that transit-oriented developments (TODs) in the Portland metro area generate far fewer car trips than standard estimates suggest—especially at sites that include affordable housing.
A 2025 report, " Portland Metro Transit-Oriented Developments (TODs): 2024 Resident Survey Findings (PDF) ," builds on a long-running PSU study tracking TOD residents since 2005 . Led by Nathan McNeil, Jennifer Dill, and Kyuri Kim, the research surveyed residents at TODs built between 2018 and 2023 across eight Oregon cities: Portland, Beaverton, Cornelius, Milwaukie, Gresham, Tigard, Hillsboro, and Happy Valley.
Learn more about this research in a seminar on October 17
Unlike previous years, most TODs and units surveyed in 2024 are targeted to serve households with 30%–80% of the area's median income. Twenty-eight of the 36 surveyed sites were categorized as affordable housing.
New survey questions explored changes in travel patterns due to the pandemic, including online shopping and work-from-home availability.
Key Findings
Fewer Cars, More Transit: TOD residents drive significantly less than predicted. Vehicle trips per housing unit were roughly half the standard estimates, and for affordable housing sites, car trips were only about a quarter to two-fifths of expected rates.
Sustainable Travel Habits: Less than half of all trips were by car. Residents relied heavily on transit (28%) and walking (19%), with a small share biking (2%). For commuting, 41% used transit regularly—far above the 7% average for Portland-area commuters.
Zero-Car Households: Half of residents at primarily affordable sites don't own a car. These households take even more transit, walking, and biking trips, showing how affordable housing near high-frequency transit supports sustainable travel.
Behavior Changes: Many residents report driving less and walking or taking transit more since moving to a TOD. About 20% have given up or are considering giving up a vehicle because of their neighborhood's walkable and transit-friendly design.
Housing Priorities Vary: Affordable housing residents prioritize cost and transit access, while market-rate residents focus on amenities, neighborhood quality, and parking availability.
Opportunities for Greater Impact
The study highlights ways to further encourage transit use, such as expanding reduced-fare passes for eligible residents and better integrating affordable TOD sites with light rail. These insights can guide planners and developers as the Portland region continues to grow.
Portland State University's Transportation Research and Education Center (TREC) is a multidisciplinary hub for all things transportation. We are home to the Initiative for Bicycle and Pedestrian Innovation (IBPI), the data programs PORTAL and BikePed Portal, the Better Block PSU program, and PSU's membership in PacTrans, the Pacific Northwest Transportation Consortium. Our continuing goal is to produce impactful research and tools for transportation decision makers, expand the diversity and capacity of the workforce, and engage students and professionals through education, seminars, and participation in research. To get updates about what's happening at TREC, sign up for our monthly newsletter
