For beginners who have just come into contact with road lighting fixtures, a series of question marks, lighting symbols? Illumination standard? That's really confusing. Below is the simplest formula for calculating average road illumination compiled by Zhuge Lighting, hoping to be helpful to everyone.

The calculation formula for average illuminance: E=F * U * K * N/S * W

E: Average illuminance

F: Light source luminous flux LM

N: Arrangement of streetlights (2 for symmetrical arrangement of N streetlights, 1 for single side and staggered arrangement)

U: Utilization coefficient 0.65 (related to the ratio of lighting distribution and installation conditions, elevation angle, pole height, and effective width of the road surface)

K: Maintenance coefficient (related to light source decay, lamp IP, and environmental cleanliness)

S: Installation spacing of street lights

W: Road width

F. The data of U and K are obtained based on the type of lamp and light source selected.

Below are a few simple sets of road lighting data for your reference:

Inverted 1, 110w high-pressure sodium lamp, pole height of 10 meters, spacing of 30 meters, effective width of road: 20-1-1, symmetrically arranged on both sides.

Using the formula for road lighting: E=2x9000x0.65x0.36/18/30=7.8Lx, the average illumination is obtained to be around 7.8LX.

Inverted 2, 110W high-pressure sodium lamp, with a pole height of 10 meters and a spacing of 28 meters. The effective width of the road is 20-1-1, arranged symmetrically in two rows.

Using the formula for road lighting: E=2x9000x0.65x0.36/18/28=8.35Lx, the average illuminance is obtained to be around 8.35LX.

Inverted 3, 150W high-pressure sodium lamp, pole height of 10 meters, spacing of 30 meters, effective width of road: 20-1-1, symmetrically arranged on both sides.

Using the formula for road lighting: 2x16000x0.65x0.36/18/30=13.8Lx, the average illumination is obtained to be around 13.8LX.

The above formula is a budget estimation formula, which can only calculate the average illuminance, but cannot calculate the minimum illuminance and illuminance uniformity. If high accuracy is required, please use lighting calculation software.