Based on research at the Rensselaer Polytechnic Institute’s Lighting Research Center, here are some preliminary specifications proposed to improve the performance of warning lights and beacons on service vehicles:
Photo courtesy of Golight Inc.
Golight LED Lighting
Golight Inc. work lamps illuminate a utility pole.
• Maximum luminous intensity – Recommends 530 candela minimum (daytime) and 180 candela minimum (nighttime); these values should prevent glare at night, while ensuring optimal response times for both daytime, and nighttime situations.
• Modulation characteristics – Recommends a 10:1 ratio between the maximum and minimum intensities while flashing; this ratio will provide improved closure detection over a source with on/off flashing.
• Spatial extent – Recommends a minimum of two beacons be used; this will result in improved closure detection over use of just a single warning beacon.
• Show direction – When lighting is intended to convey a sense of direction (like changing lanes), animated, sweeping-type signals provide more meaningful visual cues and prompt earlier lane changes, as compared to conventional flashing lights.