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Counting every space: What parking inventories tell us about cities

September 12, 2018

By David Dixon and Liza Cohen

Our planners and mobility experts offer three unique perspectives on the untapped opportunity in our parking lots, garages, and streets

The third rail of municipal politics in North America? Parking. Raise the price of meters, put in a bike corral, or green-light a condo project and you¡¯ll face a chorus of protests that boil down to this: People think parking is already unbearable and any change will make it worse.

But do perceptions of shortage match the facts? The Mortgage Bankers Association took a shot at figuring that out.?Its report,?Quantified Parking: Comprehensive Parking Inventories for Five US Cities,?combined rigorous methods and data from existing parking studies to develop a reliable count of total parking in New York; Philadelphia; Seattle; Des Moines, Iowa; and Jackson, Wyoming. MBA and its research arm call the inventories the first ¡°complete parking studies¡± for the five cities.

Generally speaking, four of the cities had much more parking than they needed (it should surprise no one that the fifth city¡ªNew York, with its density and transit network¡ªwas an outlier by every measure). But the study¡¯s author made other calculations, comparing density of parking to density of housing and jobs. Des Moines, for example, has almost?20 spaces?for each of its 83,000 households, and calculating the replacement cost of all parking (a staggering $35 billion in Seattle) suggests how much society spends on parking that might go to other activities.

We asked three experts in Â鶹´«Ã½¡¯s Urban Places to review the report and tells us what struck them about its findings.

What happens downtown?

David Dixon, FAIA, Planning and Urban Design Leader

If we think of parking as an immense piggy bank that¡¯s been locked for the seven decades since World War II, then?Quantified Parking?represents great news for downtowns. A combination of technology, demographics, and economics is about to hand us the key to the piggy bank, just when we need it.

Thanks to technology, we¡¯ll never again need as much parking to support any use as we do today. Why?

  • Shared mobility (Lyft et al.) has already cut parking requirements for uses like hotels, office buildings, and stadiums.
  • In a few years, smart cars will park themselves in smart garages, and require far less space.
  • Even GM predicts that by the late 2020s many residents of dense urban areas will shift from owning cars to sharing autonomous vehicles with low-cost, on-demand mobility ¡­ and limited need to park.

By the early 2030s¡ªeven with another 15 years¡¯ worth of development¡ªmany cities will find half or more of their parking spaces redundant. Freed from the need to build new parking, and with surface lots and unfilled garages ripe for redevelopment, many downtowns will enter an era of intensification and growing vitality.

By the early 2030s¡ªeven with another 15 years¡¯ worth of development¡ªmany cities will find half or more of their parking spaces redundant.

Demographics and economics will help them capitalize on this opportunity. Most new households formed over the next two decades in the US will comprise singles or childless couples. Those households will support trillions of dollars of investment in downtown living, working, learning, and playing. Cities can¡¯t afford to say no to this investment potential. Knowledge industries thrive in and near downtowns. Competition for firms in those fields, combined with growing fiscal pressures, will provide strong incentives for cities to grow in and up, not out.

We need to start planning now.

In planning and development terms, 2030 is tomorrow. Birmingham¡¯s Railroad Park, Boston¡¯s Seaport District, Cincinnati¡¯s Embankment, Dallas¡¯s Klyde Warren Park, San Francisco¡¯s Transbay Center¡ªplanning for these transformative downtown projects started more than a decade before the first footing was poured. None of those projects was as complex as the densification our downtowns will undergo¡ªor potentially as rewarding in terms of creating a more vital heart for the entire city, providing new revenues for tackling problems like affordability and equity, or enhancing regional economic opportunity. And there¡¯s no better way to start than by asking your community what they¡¯d like to see in place of thousands of downtown parking spaces¡ªafter first explaining why they won¡¯t need or even miss them.

What happens after you start counting?

Liza Cohen, Senior Transportation Planner

The data in?Quantified Parking?helps us see how US cities over-invested in parking. It makes clear that much of the money spent building parking (as much as $35 billion in Seattle) could have gone toward other, more efficient transportation uses. We need more hard data like this to begin making the argument for a complete shift in how we spend money on transportation improvements. Once communities have an idea of how many parking spaces they have¡ªas this report shows, it¡¯s usually more than anyone realizes¡ªthe next step is surveying occupancy.

In our experience, occupancy studies always find more parking than the study area needs to meet demand. Recently?we found?that about?half?of all spaces in downtown Chattanooga, Tennessee, were empty¡ªeven at peak hours. (The challenge, of course, is that not all parking is in the right location¡ªor in the right location at the right moment.)

Collecting data from thousands of spaces in your community might seem intimidating, but some tips and tricks we routinely use in parking studies could prove useful:

  • Pick defined but representative time periods: Early morning captures residential demand, midday captures both lunchtime and peak office demand, mid-afternoon typically shows a lull, and around 7 PM captures dinner-hour demand.
  • Tap into data already being collected automatically from:
    • Garages or lots with gate arms or card readers.
    • Digital street meters (your vendor may be able to estimate utilization based on payments, or you can create your own system to do it).
  • Consider using a drone to capture demand for on-street and surface spaces¡ªit may prove more cost-effective than sending ¡°boots on the ground.¡± Don¡¯t forget some parking may be hidden by trees!
  • Avoid special events, holidays, significant weather changes, Fridays and Mondays (when typical workday schedules tend to stray from the norm), and, if possible, significant construction.

What does it mean?

Hard data provides important backup for shifts in transportation policy. From prioritizing spending to overhauling zoning, collecting data on how people really use parking can play a pivotal role in changing how your community thinks about transportation.

  • David Dixon

    Residential Architecture Magazine named David to their Hall of Fame as ¡°the person we call to ask about cities"

    Contact David
  • Liza  Cohen

    Starting with individual people and how they make their transportation choices, Liza focuses on developing plans that expand their mobility options.

    Contact Liza
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