The University of Utah
College of Architecture + Planning

Trip and Parking Generation at Transit-Oriented Developments: Phases I and II

Dr. Ewing along with his research team is working on a project that hopes to help planners estimate trip and parking generation at transit-oriented developments (TODs). This project is funded by National Institute of Transportation and Communities (NITC). The research team for this project includes principal investigator Dr. Reid Ewing, as well as PhD students Guang Tian and Torrey Lyons.

The decision on how best to allocate land around transit stations is a debated topic, with transit officials often opting for park-and-ride lots over active uses such as multifamily housing, office, and retail organized into TODs. Providing large park-and-ride lots has been the default strategy to maximize transit ridership in the short-run. But is it the best strategy in the long run? The debate continues when land is developed, with officials usually assuming that TODs require the same number of parking spaces as conventional development. In such cases, many officials assume that transit stations near TODs require the same number of park-and-ride spaces as non-TOD stations without considering the possibility that much of the travel demand is captured internally and TODs themselves generate much of the transit demand.

Balancing the amount of parking at TODs with the need to create a pedestrian-friendly environment and encourage mixed-use development can be complicated. We define TODs using seven criteria and identify the best TODs that meet these criteria in six metropolitan areas:

  • Station Landing in Boston, MA
  • Del Mar in Los Angeles, CA
  • City College in San Diego, CA
  • Fruitvale Village in San Francisco, CA
  • Redmond TOD in Seattle, WA
  • Rhode Island Row in Washington D.C.

It is our intention to test whether TODs generate as many vehicle trips as the Institute of Transportation Engineers (ITE) Trip Generation manual estimates, and whether they need as much parking as the ITE Parking Generation manual suggests.

Consulting partners NelsonNygaard and Fehr & Peers will assist in data collection, analysis, report and article writing. Specifically, they will be conducting the parking supply and occupancy studies and building access counts along with intercept surveys. We will use this data to analyze travel modes and parking use allowing us to develop numerical models of trip and parking demand as well as recommendations for land use and parking policies at new TOD developments. A pilot study, Redmond TOD in Seattle, has been completed and submitted for publication. The other case studies will be incorporated fall 2015.

Read Our Final NITC Report (January 2017)