The long-awaited second draft of the IDA-IESNA Model Lighting Ordinance (MLO) is available and open to public review. Public comments will be accepted for 60 days, closing 23 August.

The MLO is an ordinance template jointly produced by the International Dark-Sky Association (IDA) and the Illuminating Engineering Society of North America (IESNA). Its purpose is to provide a universal guideline for effective, enforceable lighting limits in cities, towns, and states.

The first draft of the MLO was released for public review in February 2009. The bulk of input indicated that this draft was too complicated to be easily understood by the city officials it was intended to serve. In the following months the MLO Joint Task Force revised the draft. The newly released second draft incorporates many suggestions made during the first review period. One major revision is the creation of a User’s Guide that appears in tandem with the text of the ordinance to explain the ordinance in lay terms. Other revisions include the addition of optional guidelines for streetlights, a metric that measures all light sources in terms of lumen values, and a general simplification of language. Free online MLO introduction sessions are planned, with the first to be held in Tucson, Arizona on 26 June 2010.

When the final draft is released, cities of any size and budget are expected to have a tool to ensure the protection of the dark night sky while retaining the flexibility to address specific needs, such as location and population. The MLO may be especially useful to cities who are reevaluating their lighting needs to save money and energy.

More information on the MLO and the text of the current draft is available online at the IDA Web site at http://www.darksky.org/mc/page.do?sitePageId=84399&orgId=idsa. Public comments are encouraged until 23 August.