Advancing the effective use of light for society and the environment.

Vol. 1, No. 3

Thursday, October 3, 2002

LRC Works to Reduce Light Pollution in Connecticut

The LRC has three new publications to help municipalities in Connecticut reduce light pollution. A seminar to assist Connecticut municipal personnel in using the publications will follow. Current plans call for the publications to be made available to municipality representatives through the Connecticut Light & Power Web site and also through the LRC Web site. The publications are Street Lighting and Light Pollution, The Efficient Street Lighting Design Guide, and Street Lighting Design Checklist.

Street Lighting and Light Pollution is a white paper that provides information to municipalities, specifiers, designers, and other decision makers in Connecticut about street lighting and light pollution. This publication

  • outlines Connecticut legislation limiting the types of luminaires that may be used
  • discusses issues that should be considered before embarking on a lighting project
  • defines light pollution and many of the issues that surround the topic
  • summarizes good lighting practices
  • describes how municipalities can work with designers or planners to ensure that their lighting installations meets their objectives

The Efficient Street Lighting Design Guide gives examples of specific types of typical street lighting designs and presents alternative options. Although no publication could illustrate all the possible outdoor lighting scenarios, this design guide identifies practical approaches to designing efficient street lighting while considering light pollution issues. The design guide is customized for users in Connecticut and covers designs that are often used in that state.

Finally, there is Street Lighting Design Checklist, which helps decision makers think about their street lighting projects. The checklist covers lighting objectives such as safety, economic development, aesthetics, and energy efficiency. The checklist asks people involved in lighting projects to consider the goals for their projects and what the most appropriate ways to achieve those goals might be.

These publications came about because a new state law in Connecticut requires municipalities to use full cutoff luminaires for any new or replacement public lighting, but many municipalities lack information about how to use these luminaires effectively. "Connecticut Light & Power came to us about this problem," says LRC researcher Michele McColgan, Ph.D., "and we proposed this project as the way to meet the need. They asked us to produce the three publications and follow up with a seminar in which municipal employees can learn directly from LRC staff members." The seminar will cover how to use these materials.

McColgan thinks that the LRC may do the same for other groups in the future. "With all the pending legislation," she says, "there will be a need for this kind of information in other states, too."

People all over North America are concerned about the effect that outdoor lighting has on their ability to see the night sky. Legislation often requires a reduction of the amount of light street lights put on roads and the use of full cutoff luminaires, which some people believe decrease sky glow.

"But there's more to it than that," McColgan says. "We want to go about this in a scientific manner, recommending measures that we know through research will do the job, and full cutoff luminaires are really designed to reduce glare, not light pollution. So we think the matter needs more study, especially in the area of light that's reflected back up from the ground. A new luminaire classification might be needed."

McColgan sees a continuing need for work on this topic. "We spent almost a year putting these publications together, and it's been a useful project—one we're pleased to have been a part of," she says. "Next I'd like to see us get involved in more research projects. Research and education go hand in hand, and both are going to be required if we're to succeed in reducing light pollution."

For more information about these publications, contact Michele McColgan at

2002 Rensselaer Polytechnic Institute, Troy, NY 12180 USA.

Rennselear Polytechnic Institute