Too much parking is a waste of money and space: lessons from Seattle

Ann Cheng Headshot

Right Size ParkingFrom the city center to the suburbs, there’s an oversupply of parking – and it’s costing us all a lot of money.

You might find this hard to believe. We’ve all suffered in the search for parking, scouring crowded city streets and parking lots for an empty space, inevitably when you’re already late and trying to ignore the mobile phone buzzing with someone wondering about your whereabouts.

But as Daniel Rowe of King County Metro Transit shared at a brownbag at TransForm last week, residential buildings throughout the Seattle area are saddled with approximately 40% too many parking spaces compared to what is actually being used, on average. And it doesn’t matter whether you’re in the central business district of a city or a spread-out suburb, either. There’s too much parking in all types of communities.

Rowe is the lead staffer for Right Size Parking, a project that seeks to help cities and developers strike a balance between parking supply and demand. He came to TransForm last Thursday to tell us about the work they’ve been doing and help with our GreenTRIP Connect project, which we’ll be launching this fall.

What’s so bad about a parking oversupply? If nothing else, it’s expensive. Rowe calculates that for a typical suburban multifamily project with 150 homes, roughly $800,000 is spent to build parking spaces that will sit vacant. That increases the average cost of living in one of those homes by over $5,000 – whether through increased rent, fees, and/or purchase price. For developers, that $800,000 could be invested in other amenities for residents, or used to underwrite affordable housing units – or not needed at all, making it easier to raise the capital to complete a residential housing development.

Too much parking is also a well-documented contributor to increased automobile ownership, congestion, and pollution. Particularly in transit-rich neighborhoods, new housing can lead to a reduction in public transportation ridership if new homes attract residents who are used to driving, and enable them to keep doing so. Parking oversupply can silently undermine our best intentions for cleaner air, safer streets, and affordable homes – but it can be difficult to avoid, especially when zoning codes and city ordinances require more parking than is actually needed.

So King County Metro Transit created the Right Size Parking Calculator to help cities and developers assess the right amount of parking for residential buildings, based on where the project is located as well as building characteristics. A developer can use the online calculator to evaluate how much parking a proposed project should include, and city planners are using the tool to review land-use policies and make sure they’re not overburdening their communities with too much parking.

Instead of paying for unused parking spaces, First Community Housing provides
free transit passes for all residents, saving money for everyone.
First Community Housing family with transit passes

With projections calling for over 400,000 new homes in the next 25 years to accommodate population growth in the Bay Area, extra unused parking could cost a fortune. At a conservative estimate of $20,000 per parking space, the price tag for an average oversupply similar to King County’s would be upward of $3.2 billion.

This money would be better spent on transportation improvements that get people moving. The entire International Boulevard Bus Rapid Transit Project will cost a measly $216 million in comparison. Building the right amount of parking – instead of too much – could free up enough money to fund more than a dozen BRT lines or hundreds of miles of pedestrian safety improvements.

That’s why TransForm is working on a similar tool for our region through our GreenTRIP Connect initiative. We were excited to learn more about the Right Size Parking project as we prepare to launch the data collection phase of GreenTRIP Connect this fall. For more information, visit our GreenTRIP webpage.

You can check out the slides from Daniel Rowe’s presentation here.


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