If you have ever wondered how bright street lights are and how they are measured, this blog post will answer your questions.
Street lights are essential for providing visibility and safety on roads, sidewalks, parking lots, and other public spaces at night.
But how do we know how much light they produce and what factors affect their brightness?
One way to measure the brightness of street lights is by using lumens (lm), which are units of luminous flux or light output.
Lumens indicate how much visible light a source emits per unit of time. The higher the lumen value, the brighter the light source.
However, lumens alone are not enough to determine how well a street light illuminates an area.
Other factors such as beam angle, color temperature, mounting height, spacing, and orientation also play a role in creating optimal lighting conditions.
Beam angle refers to the spread of light from a source in degrees. A narrow beam angle concentrates light on a smaller area, while a wide beam angle covers more ground. Color temperature describes the hue or tone of white light from warm (yellowish) to cool (bluish). A lower color temperature creates a warmer and more relaxing atmosphere, while a higher color temperature produces a cooler and more alerting effect.
Mounting height is the distance from the ground to the top of the street light fixture. It affects how far and wide the light reaches and how much it is affected by glare or shadows.
Spacing is the distance between adjacent street lights along a road or path. It determines how uniform and consistent the lighting level is across an area.
Orientation is the direction that the street light faces relative to the road or path. It influences how well it illuminates pedestrians, vehicles, signs, and other objects.
So how many lumens is a typical street light?
According to Lsleds , 5000 lm is used in residential areas where lower brightness levels are acceptable. Depending on lanes and spacing requirements for different types of roads, collector roads would need between 7500 lm and 15000 lm per fixture , while arterial roads would require between 15000 lm and 25000 lm per fixture.
Below is a table of different watt LED street light lumens in different installation height for your reference.
|Lamp Power(W)||Lumens(LM)||Installation Height(M)||Pole distance(M)|
The International Dark-Sky Association (IDA) recommends that street lights have a correlated color temperature (CCT) of 3000K or less . This means that they should have a warm white glow that mimics natural moonlight or candlelight rather than daylight-like blue-white light that can disrupt circadian rhythms and cause ecological problems for wildlife.
Street lights are an important part of urban infrastructure that provide safety and convenience for people at night. By understanding how they are measured by lumens and other factors such as beam angle, color temperature, mounting height, spacing ,and orientation ,we can design better lighting solutions that meet our needs without wasting energy or harming our environment.