Design Factors That Guide LED Street Lighting

Street lights are primarily meant to provide appropriate lighting levels for pedestrians and motorists, but they also make environments more attractive. Though most municipalities used halide and fluorescent bulbs in the past, they have now switched to LED street lighting to boost their energy efficiency and benefit from the long lifespan of LED bulbs. When choosing the design for installing street lights, here are the determinants that should guide you.

Average road luminance

Road luminance measures a road's visibility. This determines whether a motorist or pedestrian can clearly see obstacles. The ideal road luminance ensures that road users can see an obstacle's outline. Road luminance depends on your luminaire's lumen output, road surface reflective properties, and the luminaire's light distribution. Generally, a higher brightness level means better lighting. The ideal average road luminance is 0.3-2.0 Cd/m2.

Uniformity

This is an index that measures a road's uniform light distribution. It is defined as a ratio of the average road's brightness and its minimum brightness. Optimal overall uniformity for LED street lighting ensures that all objects and points in a road are illuminated sufficiently for people to see. Experts recommend a uniformity value of 4.0 for road lighting. Longitudinal uniformity refers to a difference between the darkest and brightest sections of a street's centerline. Optimal longitudinal uniformity reduces low and high brightness patterns on straight and long roads.

Glare

This is a blinding sensation when the brightness of LED street lighting exceeds the human eye's adaptation level to light. Glare leads to reduced visibility and discomfort. The ideal industry glare level for street lights is 10-20%.

Pubic lighting is not as easy as simply installing a few fixtures along the street. It should focus on the above design elements to ensure it delivers appropriate lighting and does not become a hazard. Thankfully, there are lighting simulations you can use to envision the best lighting design for your street before settling on one.