Blinding glare must not be tolerated. Disability glare should also be prevented, since such glare can affect the ability of drivers to perceive objects or obstructions clearly. It should be noted that discomfort glare may cause fatigue which may result in driver error. There are instruments that can measure the level of glare. Cutoff Light Fixtures Are Recommended Cutoff luminaires should be considered the first choice in design.
Some people refer to cutoff light fixtures as lights with shields.
Actually, streetlights, parking lot lights, and many other types of lighting that are designed as cutoff do not require separate shields or visors and cost about the same as non-cutoff types. The evidence is clear that the lighting of roadways benefits the public, but most of the lighting being installed could have done the job even better, at no additional cost. Cutoff designs for parking lots and other area lighting will also provide more effective illumination. The New Jersey Department of Transportation has revised its roadway lighting policy and is now maximizing the use of cutoff luminaires to improve the quality of lighting. The New Jersey Highway Authority is presently installing only cutoff lighting as new installations and replacements on the Garden State Parkway.