Optimal Roadway Lighting Design


MDOT replaced more than 200 inefficient high-pressure sodium (HPS) roadway fixtures on Interstate 94 as part of the innovative lighting demonstration. The project was supported by MI Department of Licensing and Regulatory Affairs, formerly the Department of Energy, Labor and Economic Growth. MDOT selected EverLast® induction cobra head roadway fixtures from Jackson, Michigan based lighting manufacturer Full Spectrum Solutions, Inc. as replacements for HPS fixtures. MDOT was able to replace 400w main line and 250w ramp fixtures with 150w Induction fixtures. The retrofit on the main line will result in energy savings of nearly 65%, and the savings on the ramps will exceed 40%. This type of energy reduction will save the state significant amounts of money, especially if it were to be implemented statewide. The roadway fixtures by EverLast® were selected primarily because of their low glare and enhanced optical design, enabling them to light more effectively from pole to pole and meet the strict design specifications of the DOT. Pole spacing in areas of the demonstration is up to 240 ft with 40 ft mounting height. In addition, the new induction lights have a 100,000 hour rated lamp life, meaning reduced maintenance cost and increasing worker safety.