When you have parking lot lights to replace or install, it’s critical to make a plan of where to place all of them throughout the parking lot. There are many factors to consider when it comes to safety, visibility, and logistics of installation. Read the rest of this post to determine optimal placement for your parking lights.
Top things to consider when laying out parking lot lights:
- Style of Parking Lot Lights
- Vicinity of Surrounding Buildings
- Required Parking Lot Light Levels
- Allowed Height of Parking Light Poles
Style of Parking Lot Lights
Picking the correct fixture is key to keeping the quantity of lights and spacing to a minimum in a your parking lot. One factor to consider in selecting a luminaire is the LER factor of a fixture. The U.S Department of Energy recommends a LER rating of at least 65. To calculate the LER value of an LED, divide: luminaire light output (lumens) / input power (watts).
Vicinity of Surrounding Buildings
While doing the initial site survey for parking lot lights, pay close attention to adjacent building locations and how the public enters and exits the parking lot. To help avoid light trespass or glare coming from the fixture, implement light shields. The four cutoff classifications based on luminous intensity are non-cutoff, semi-cutoff, cutoff, and full-cutoff. Using the correct optic will also help with minimizing light trespass.
Required Parking Lot Light Levels
The RP-20-98 Parking Lot Illuminance Recommendations uses the following table for its recommended light levels.
|Minimum Horizontal Illuminance||
|Uniformity Ratio, Maximum to Minimum||
|Minimum Vertical Illuminance||
Light levels at the property line should not exceed 0.1 fc when adjacent to business properties, and 0.05 fc at residential property boundaries.
Allowed Height of Parking Light Poles
Many counties will list a maximum allowable height for light poles, and thus should be taken into consideration before the design stage. The area of the parking lot will typically determine the height of the light pole. In densely populated areas, shorter poles will ensure that glare does not become an issue, but more light poles will be needed offer good coverage (especially when compared to rural settings, where taller—and fewer—poles can achieve the same uniformity without the worry of glare due to less public interaction). The designer can use the glare rating or the veiling luminance of the light to ensure that the angle of discomfort does not fall outside of the property line.
Take a look at The Dark Sky Society’s guide to gain a better understanding of how to determine optimal placement for your parking lot lights.
There is no one size fits all to parking lot light design, but keeping in mind the above tips will ensure a coherent design that fits between delivering enough light for safety but not too much to cause a public nuisance. Have other tips for optimal placement of parking lots? Let us know in the comments.