The city of Portland, Oregon (529,000), has replaced almost all of the red and green incandescent light bulbs in its traffic signals with light-emitting diodes (LEDs). LEDs last three to five times longer than incandescent bulbs and use 80–90 percent less electricity, although they are more expensive to purchase. Moreover, while incandescent bulbs burn out immediately, LEDs just become fainter over time; this gives maintenance workers time to replace LEDs before public safety is jeopardized. The city is leasing the LEDs for five years and has the option of keeping them after that period. The initial cost of the LEDs was $2 million (the price of LEDs has dropped since Portland purchased them), but the city received $700,000 in incentive payments from the electric utility. With the saving of $350,000 a year in electricity costs and an additional $50,000 worth of reduced maintenance, the LEDs are expected to pay for themselves within three years. Bill Kloos Signal System Operator City of Portland 1120 Southwest Fifth Avenue, 9th Floor Portland, OR 97204 503/823-5382 E-mail: bill.kloos@trans.ci.Portland.org.us Web site: www.sustainableportland.org/energy_gov_challenge.html