Parking occupancy is the share of parking spaces in use at a given moment: the number of parked vehicles divided by the number of spaces. It is the most basic measure of how well a parking supply matches demand.
Occupancy is usually measured by counts at set times through the day, by sensors, or by license plate recognition and payment data. Peak occupancy matters most for planning, while occupancy across the day shows how much of the supply sits idle.
The 85% target
Many cities and planners aim for peak on-street occupancy around 85%, roughly one open space per block face. The idea, popularized by Donald Shoup and put into practice by programs such as SFpark, is that above that level drivers start circling for the last space, and below it the curb is underused. In off-street facilities, a similar cushion is built in as effective supply.
Using occupancy data
- Set and adjust prices block by block or facility by facility. See dynamic pricing.
- Decide whether new supply is really needed. See parking utilization studies.
- Identify underused facilities that can be shared with nearby uses.
- Feed guidance systems that direct drivers to open spaces.
The Parkonomics view
Occupancy turns arguments about “not enough parking” into numbers. Most districts that feel full are full only on a few blocks for a few hours.
Related terms: Effective Supply, Dynamic Pricing, Parking Utilization Studies, Cruising for Parking, Parking Turnover
Further reading: Pricing the Curb