Induction lamps are high frequency (HF) light sources, which follow the same basic principles of converting electrical power into visible radiation as conventional fluorescent lamps. The life of induction lamps on the market today reaches 100,000 hours. This makes it beneficial to use such lamps in applications where lamp maintenance is expensive. They cost significantly less than LED lights and are capable of producing a wide range of color and they maintain lumen (light) output over their life. LED (light-emitting diodes)Currently all of the City’s traffic signals are equipped with LED lights. Over the past few years, we have replaced our traffic signal incandescent lamps with LED lamps, resulting in significant energy savings. LED’s cost significantly more upfront than the high pressure sodium bulbs. LED lights use less energy and last longer than conventional bulbs, which could result in savings on energy and maintenance costs over time. LED light produce a whiter type of light, and do not contain mercury. High Pressure Sodium (HPS)Currently all the City street light are equipped with High Pressure Sodium lamps. They are energy efficient—consuming about 125 watts of power and affordable in cost. HPS lights are used widely for outdoor lighting; many cities are illuminated with high pressure sodium bulbs. These bulbs do contain a small amount of mercury. HPS lamps cost significantly less than both LED and Inductive lamps.