Several states, including Connecticut, and many municipalities have adopted legislation designed to limit light pollution from streetlights and other fixtures. Among the rationales for such measures have been energy conservation, the reduction of glare and its resulting traffic hazards, and a desire to allow people a better view of the night sky. There are several Websites about such "dark skies" initiatives, including


The law requires that a roadway lighting system funded by the state (1) be designed to maximize energy conservation and minimize glare and light spilling onto adjoining properties and (2) provide the minimum amount of lighting needed for its purpose. State funds can be used only if the Department of Transportation determines that the lighting needs cannot be met by other means such as reducing the speed limit in the area or installing passive lighting. The latter approach includes reflectorized roadway markings, lines, warnings, and informational signs.

Lights with a capacity of 1,800 lumens (the light produced by a 125 watt bulb) or more on the states secondary and special service highways must be designed to prevent light going above the lamp, (i.e., be equipped with a full cutoff luminaire). This requirement does not apply if it would compromise the highways safety, increase the lighting's cost, or violate federal law.

The transportation commissioner can waive the requirement if he determines it is necessary. Waiver requests must describe the lighting plan and the efforts the applicant has made to comply with the requirement and include other information the commissioner requires. In reviewing the request, the commissioner must consider design safety, costs, and other factors he considers appropriate.

These provisions do not apply if the Office of Policy and Management (1) analyzes the lifetime cost of fixtures that meet these requirements and fixtures that do not and (2) certifies that the fixtures that meet the requirements are not cost effective and are not the best alternative. The law does not apply to lighting meant to be used for less than seven days (CGS § 13a-110).


The law requires that all outdoor light fixtures (other than airport navigational lights) be fully or partially shielded. Fully shielded means that no light goes above the bottom of the lamp; partially shielded means that that the shield extends at least halfway down the lamp. This requirement does not apply to incandescent lights of 150 watts or less and other sources of 70 watts or less. Streetlights are exempt from this requirement if the shielding is not available from the manufacturer.

Unlike the laws in Connecticut, this requirement applies to all lighting, rather than just that funded by the state. Nonconforming lights can be used if they automatically shut off between midnight and dawn. Arizona has prohibited the installation of new mercury vapor lamps since 1991. Counties and municipalities can adopt more stringent standards. (Ariz. Rev. Stat. § 49-1101 et seq.)


Maine's law applies to all state-funded lighting fixtures. It bars the use of state funds to install or replace outdoor fixtures that exceed the minimum lighting level recommended for the application by the Illuminating Engineering Society of America or the U.S. Department of Transportation. As in Connecticut, fixtures with a rated output of 1,800 lumens must be designed so that no light goes above the lamp. In the case of highways, lighting is only allowed when non-lighting measures cannot achieve the desired result. In addition, the Highway Commissioner must consider the minimization of glare and light trespass (light shining on neighboring properties).

The only exceptions to these requirements are when (1) federal law has conflicting requirements or (2) the director of the Bureau of Public Improvements determines that there is a compelling safety interest that cannot be met while complying with the state law (5 Me. Rev. Stat. Ann. § 1769, 2.23 Me. Rev. Stat. Ann. § 707)

New Mexico

The law requires that new outdoor night lighting, with certain exceptions, be shielded below horizon level or shut off after 11 p.m. It requires that nonconforming existing fixtures be replaced with conforming fixtures when they become inoperable. Agricultural, industrial, and mining or oil and gas facilities, and billboard lighting on interstates and federal primary highways are exempt from these requirements. Public utilities can adjust rates to recover the replacement costs (N.M. Stat. Ann. § 74-12-1 through 74-12-10).


The law bars state funds being used to install, replace, or operate outdoor lighting fixtures unless:

The requirements do not apply to temporary lighting and lighting used solely to enhance the aesthetic beauty of an object. Nor do they apply when compliance would violate federal law or when there is a compelling safety interest that cannot be met by other means (Tex. Health and Safety Code Ann. § 421.001 et seq.).

Model Light Pollution Regulations for a Municipality

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