Parking Demand Analysis: How Parking Need Is Estimated

A parking demand analysis estimates how many parking spaces a site, building or district needs, at what times, and for which users.

For an existing area, it starts with counts of how parking is actually used. For a new project, it builds demand from the planned land uses, adjusted for location, transit, pricing and sharing among uses. The result is a recommended supply, usually expressed as a design-hour demand plus a small cushion so drivers can find a space. See parking utilization studies and effective supply.

How a demand study is built

Base rates. Demand per unit of each land use, from local data or published sources such as ITE. See ITE.
Adjustments. Mode share, transit access, pricing and captive users already on site.
Time of day and season. Each use peaks at different hours; shared parking combines them.
Design hour. The hour the supply is designed for, often not the single busiest hour of the year. See design day and design hour.
Cushion. Extra spaces so the facility does not feel full, often 5 to 15 percent.

Common mistakes

Using code minimums or national averages as if they were measured demand.
Designing for the busiest day of the year rather than a typical busy day.
Ignoring price: free parking produces more demand than priced parking.

The Parkonomics view

A demand study is the cheapest money spent on a parking project, because it decides how much of the expensive part to build. Ask what was counted, what was assumed, and how the answer changes if parking is priced.