Introduction

Roadway lighting systems are coming under greater scrutiny from various sectors of the public. Issues such as glare, sky glow, and aesthetic lighting have achieved widespread attention and are open to criticism. Lighting designers should become familiar with these issues and be prepared to design lighting systems that meet required illumination levels while also considering the environmental and aesthetic effects.
Communities are adopting lighting ordinances meant to reduce sky glow (popularly termed “light pollution”). Lighting designers should be on notice that this is a very important issue. Light emitted above the horizontal does not benefit roadway lighting, but it can contribute to glare and may be considered visual clutter. Many people consider sky glow undesirable and even offensive. This is an important issue with the astronomical community, and is particularly annoying when equally effective lighting systems can be designed that reduce or eliminate up-lighting.