Smart Growth America’s new study questions parking requirements at transit-oriented developments


Community revitalization advocacy, Smart Growth America (SGA), has released a new report that questions standard industry guidelines on how much parking is required at transit-oriented developments (TODs), and the number of vehicle journeys they generate.

The land near transit stations is a valuable commodity. Hundreds or thousands of people travel to and through these places each day, and decisions about what to do with this land have implications for local economies, transit ridership, residents’ access to opportunity, and overall quality of life for everyone in a community. Many communities choose to dedicate at least some of that land for parking, but the key question is, how much? Standard engineering guidelines, such as the Institute of Transportation Engineers’ (ITE) Trip Generation and Parking Generation guides, are designed for mostly isolated suburban land uses, not walkable, urban places served by transit. But few alternative guidelines for engineers exist, so despite these shortcomings many planners continue to use ITE’s publications.

The study covered in the new report, Empty Spaces: Real parking needs at five TODs, set out to determine how much less parking is required at TODs and how many fewer vehicle trips are generated than standard industry estimates. Professor Reid Ewing and his research team at the University of Utah’s College of Architecture + Planning selected five TODs across the country, each with a slightly different approach to development and parking: Englewood, Colorado; Wilshire/Vermont in Los Angeles, California; Fruitvale Transit Village in Oakland, California; Redmond, Washington state; and Rhode Island Row in Washington, DC. The research team, together with two transportation consultancies, Fehr & Peers Associates and NelsonNygaard Consulting Associates, counted the number of people entering and exiting the TOD buildings, and conducted brief intercept surveys of a sample of them. The team also counted parking inventory and occupancy.

The study found that all five TODs generated fewer vehicle trips than standard guidelines estimate, and used less parking than many regulations require for similar land uses. Most of the TODs included in this study also built less parking than recommended by engineering guides, yet even this reduced amount of parking was not used to capacity: the ratio of demand to actual supply was between 58-84%.

Fewer vehicle trips is one likely reason why parking occupancy rates were lower than expected. Another possible reason is that standard engineering guidelines do not fully account for other travel modes that are available and actively encouraged at TODs. In each of the five TODs studied, at least 33% of trips were taken by modes other than driving.

Developers, regulators, and practitioners are already rethinking how much parking is needed at TODs. These findings underscore the obvious need for planners to rethink how they use parking guidelines intended for suburban development not served by transit. This new information can help them make better informed decisions, and ultimately create the development needed most at these in-demand locations.

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About Author


Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).