Parking Guidance Systems: How They Work and What to Buy

A parking guidance system (PGS) detects which spaces are open and directs drivers to them, using count signs at entries and decision points and, in space-level systems, indicator lights over each stall.

A guidance system counts open spaces and shows them, on signs at each level and lights over each stall, so drivers aim for green instead of circling. Less hunting means less congestion, less frustration, and lower emissions inside the deck. Illustrative.

Systems range from simple level counts, based on vehicles entering and leaving each floor, to space-by-space detection with ultrasonic sensors or cameras. Camera-based systems can also read plates to help drivers find their car and supply data for enforcement and analytics.

Try it

Find a space, with and without guidance

A 384-stall garage on four levels. The lower levels fill first, and some open stalls hide behind big SUVs. Set how full the garage is, then turn on level counts and stall lights.

Below about 85 percent occupancy a driver finds a space in the first aisle or two, with or without guidance. Above 90 percent, an unguided driver searches level by level and can miss hidden stalls entirely, while level counts and stall lights send the driver straight to the right level and stall. Shorter searches mean fewer cars circling the ramps at the same time.

Illustrative: 5 mph search speed, 9-foot stalls, 200 feet per ramp, 5 arrivals a minute at peak, about a third of open stalls hidden from an aisle without stall lights.

Types

Count-based. Counts vehicles in and out of a facility or level; lower cost, less precise.
Single-space sensors. One sensor per stall with a light showing open or occupied.
Camera-based. Each camera watches several stalls; can add plate reading and find-my-car.

Benefits

Shorter search times and less circling, emissions and congestion inside the facility.
Higher effective capacity, because drivers find the last open stalls. See effective supply.
Occupancy data for pricing and operations.

Guidance does not have to stop at the facility entrance. The same space counts can feed apps, navigation services and websites, so drivers choose a facility before they arrive, and can show monthly parkers and permit holders where their spaces are open.

Maintenance

Counts drift and sensors fail; plan for regular calibration and reconciliation. A wrong green light costs more goodwill than no light.

The Parkonomics view

Guidance converts capacity you already own into capacity drivers can find. It pays best in busy, multi-level facilities where the last 15 percent of spaces are hard to see.

Related terms: Dynamic Signage, Wayfinding, Effective Supply, LPR