IES RP-8-22 is the standard that defines how well parking lots should be lit. Most commercial properties with aging HID fixtures fail it — and most owners do not know.
The standards
| Area | Minimum Light Level | Uniformity Ratio |
|------|-------------------|-----------------|
| Basic parking (low activity) | 0.2 fc | 20:1 |
| General parking (medium) | 0.5 fc | 15:1 |
| Enhanced security (high) | 1.0-2.0 fc | 10:1-15:1 |
| Pedestrian walkways | 1.0-2.0 fc | 4:1 |
| Building entrances | 5.0 fc | — |
Our standard commercial auditing target is **2.0 fc with 15:1-20:1 uniformity**.
Why HID systems fail
Metal halide lamps lose 30-50% of their lumens in the first 40% of rated life. A 400W MH fixture that produced 36,000 lumens new might be outputting 18,000 lumens after two years — while still drawing the same 450W.
You are paying full electricity for half the light.
Uniformity matters more than brightness
A parking lot with 5.0 fc average but dark spots between poles is more dangerous than one with 1.0 fc uniform coverage. The dark spots are where incidents happen.
**NYC study:** Bright, uniform outdoor lighting produced a **39% reduction in nighttime crime**. The Philadelphia LED rollout showed statistically significant crime reductions across all retrofitted areas.
The liability angle
When an incident occurs in a poorly lit parking area, the first thing an attorney requests is a lighting survey. If your lot does not meet IES RP-8-22, you have a documentation problem.
LED retrofits with proper photometric design solve both the light level and uniformity issues simultaneously. Every project we do includes IES-compliant photometric layouts and post-install verification.
What 4,000K CCT means for safety
We specify 4,000K (neutral white) for most commercial parking applications: