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Lighting Relative to Pedestrian Safety

The essential purpose of various lighting systems is to provide illumination of a certain quality and quantity sufficient for safety, to enhance visibility of one’s surroundings, and aid in the performance of certain tasks, including the speed and accuracy required by such tasks. The adequacy of such lighting depends on the type of environment involved, the specific tasks to be performed, and the capabilities and limitations of the persons reasonably anticipated to utilize such environments or perform such tasks. While lighting can be used for aesthetics, to improve general visibility, or to increase productivity, the most essential purpose of lighting is to provide sufficient illumination for safety, and for such purposes, the safety literature recommends or requires certain minimum levels of illumination.

The table below outlines information from the authoritative Illuminating Engineering Society of North America, IES Lighting Handbook (1981, 1987, 1993), indicating the absolute minimum illuminance levels for safety must be at least 0.5 to 5 footcandles, depending on the hazards present requiring visual detection and the normal activity level of the area.

Illuminance Levels for Safety
Hazards Requiring Visual Detection Slight High
Normal Activity Level Low High Low High
Illuminance Levels (Footcandles) 0.5 1 2 5

For example, regarding the critical importance of detecting the presence of a change of elevation (potential trip-type hazard, single step, short stairway, or the tread/riser dimensions and leading edges of a standard stairway), when applying the above information contained in the above table to these situations, the "hazards requiring visual detection" must be considered "high," with subsequent absolute minimum illuminance levels for safety being 2 to 5 footcandles.

Major national codes and standards, including the International Building Code (IBC) and its predecessors (Uniform Building Code, Standard Building Code, BOCA/National Building Code), the NFPA 101 Life Safety Code, and others, also require the means of egress of any occupied building or facility to be illuminated to a minimum of at least 1 footcandle measured at floor level.

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