Glare in Parking Facility Lighting

Glare is excessive brightness or contrast in the field of view that causes discomfort or makes it harder to see.

Glare is light that reaches the eye instead of the ground. A bare fixture scatters it everywhere, creating bright sources and dark shadows that hide people; a shielded, full-cutoff fixture puts the same light on the deck where it belongs. More lumens is not the fix; aiming them is. Illustrative.

In a parking facility glare matters for safety: a driver squinting into a bare fixture may not see a pedestrian, and a camera can be blinded by a bright source. It is a frequent complaint after poorly chosen LED retrofits, where very bright, small light sources replace older fixtures. See LED lighting.

Types of glare

Disability glare reduces visibility, such as headlights or a bright fixture near the line of sight.
Discomfort glare is annoying or tiring without directly blocking vision.
Reflected glare comes off shiny surfaces such as wet pavement or glossy paint.

How design limits it

Shielded and cutoff luminaires that hide the light source from normal view angles.
Lenses and optics that spread light rather than concentrating it.
Light-colored ceilings and walls that raise brightness evenly. See luminance.
Entrance lighting that steps down gradually from daylight, so drivers’ eyes can adjust.
Guidance from the Illuminating Engineering Society.

The Parkonomics view

More light is not the same as better light. In a garage, even, glare-free light makes people feel safer than bright spots and dark corners.