Towns and counties often develop an Outdoor Lighting Ordinance to regulate outdoor lighting. Light trespass and shielding are two important issues for public policy to consider. No direct light from any source (including streetlights) should reach another property. Adequate shielding keeps light contained to the area that needs to be lit.
Recommended Best Practices
The Illuminating Engineering Society (IES) and the International Dark-sky Association (IDA) have jointly issued this set of recommendations.
For specific recommendations, see the Lights Out Colorado pages on public lighting.
Light Trespass and Glare
Light trespass can be a serious problem for residents. Studies show that it can result in health problems.
Lighting Policy Annotated Bibliography
This document gives Colorado advocates a reference to the articles important to discussions with local governments.
Many of these articles are difficult to find.
A comparison of various outdoor lighting ordinances, as found in the bibliography.