1. Introduction

This issues and options paper summarizes the technology of LED traffic signals, and provides information about their performance in various installations. Energy use, visibility, electrical characteristics, reliability and maintenance are considered. Both potential advantages and potential disadvantages to this technology are stated. Several strategic approaches to the implementation of LED traffic signals are described. We offer some preliminary recommendations about the roles that could be played by municipalities, electric utilities, energy service companies, and researchers in ensuring that LED technologies are applied appropriately.

The issues that are discussed fall into six primary categories: codes and specifications, energy, cost, visibility, power and environmental factors, and market issues. Of course, each of these sets of issues are interrelated, with no clear boundaries between them.

The Lighting Research Center (LRC) acknowledges the support of Hewlett Packard Optoelectronics Division, the New York State Energy Research and Development Authority, Pacific Gas and Electric Company, and the U.S Environmental Protection Agency. These organizations sponsor the LRC's Lighting Transformations Program, which has produced this paper.

1. INTRODUCTION
2. TRAFFIC SIGNALS
3. CODES AND SPECIFICATIONS
4. ENERGY
5. COST
6. VISIBILITY
7. OPERATION: POWER AND ENVIRONMENT
8. MARKET ISSUES: SUPPLY AND DEMAND
9. OTHER APPLICATIONS
10. PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS
11. REFERENCES