Are traffic signal indications using light emitting diodes (LEDs) in conformance with the MUTCD?
Yes, as long as they comply with the applicable ITE standards. The MUTCD does not specify the type of light source used for traffic control signal indications. Section 4D.06 states, “Support: Research has resulted in signal optical units that are not lenses, such as, but not limited to, light-emitting diode (LED) traffic signal modules.” It also states, “Standard: References to signal lenses in this section shall not be used to limit signal optical units to incandescent lamps within optical assemblies that include lenses.” However, Section 4D.06 also requires the design, illumination, and color all signal indications, including those using Led’s, to meet the requirements of the “Standards for Vehicle Traffic Control Signal Heads” published by the Institute of Transportation Engineers (ITE). The intensity and distribution of light from each illuminated signal lens should also conform to the ITE standards. ITE updated those standards in 2005 (information available at http://www.ite.org/s
