In this chapter:

(1) “Cutoff luminaire” means a luminaire in which 2.5% or less of the lamp lumens are emitted above a horizontal plane through the luminaire’s lowest part and 10% or less of the lamp lumens are emitted at a vertical angle 80 degrees above the luminaire’s lowest point.

(2) “Light pollution” means the night sky glow caused by the scattering of artificial light in the atmosphere.

(3) “Lumen” means a standard measure of luminous flux representing the quantity of visible light output.

(4) “Luminaire” means a complete lighting unit, often referred to as a “light fixture”. A luminaire consists of the lamp, optical reflector and housing, and electrical components for safely starting and operating the lamp.

(5) “Outdoor lighting fixture” means any type of fixed or movable lighting equipment that is designed or used for illumination outdoors. The term includes billboard lighting, street lights, searchlights and other lighting used for advertising purposes, and area lighting. The term does not include lighting equipment that is required by law to be installed on motor vehicles or lighting required for the safe operation of aircraft.

(6) “State funds” means:

a. Money appropriated by the legislature; or

b. Bond revenues of the State.

75 Del. Laws, c. 202, §  1; 

(a) An outdoor lighting fixture may be designed, installed or replaced using state funds only if:

(1) The new or replacement outdoor lighting fixture is a cutoff luminaire if the rated output of the outdoor lighting fixture is greater than 1,800 lumens;

(2) The minimum illuminance adequate for the intended purpose is used with consideration given to nationally recognized standards;

(3) For lighting of a designated highway of the state highway system, the Department of Transportation determines that the purpose of the outdoor lighting fixture cannot be achieved by the installation of reflective road markers, lines, warning or information signs, or other effective passive methods; and

(4) Full consideration has been given to the Department of Transportation’s Traffic Lighting Policy, energy conservation, reducing glare, minimizing light pollution, and preserving the natural night environment.

(b) For purposes of paragraph (a)(4) of this section, “energy conservation” means reducing energy costs and resources used and includes using a light with lower wattage or a timer switch.

(c) Subsection (a) of this section does not apply if:

(1) A federal law, rule, or regulation preempts state law;

(2) The outdoor lighting fixture is used on a temporary basis because emergency personnel require additional illumination for emergency procedures;

(3) The outdoor lighting fixture is used on a temporary basis for nighttime work;

(4) Special events or situations require additional illumination;

(5) The outdoor lighting fixture is used solely to enhance the aesthetic beauty of an object;

(6) A compelling safety interest exists that cannot be addressed by another method;

(7) The new or replacement outdoor lighting fixture is to be installed and operated on roadways and supporting interchanges that are classified by the Department of Transportation’s Functional Classification Maps as interstate or other freeway/expressways within the urbanized boundaries and other principal arterials that are designed to interstate or freeway/expressway standards in nonurbanized areas; or

(8) As to maintenance of existing lighting systems, the change to a cutoff luminaire would require the redesign and reconstruction of the system to compensate for the different lighting characteristics of these fixtures.

(d) Special events or situations that may require additional illumination include sporting events and illumination of monuments, historic structures, or flags. Illumination for special events or situations must be installed to shield the outdoor lighting fixtures from direct view and to minimize upward lighting and light pollution.

75 Del. Laws, c. 202, §  1;  77 Del. Laws, c. 278, §  1;