This Lighting Measurements Guide provides approved test procedures and methods of reporting data that promote the uniform evaluation of the photometric performance of roadway luminaires using mercury, metal halide, high pressure sodium, or incandescent filament lamps. Low pressure sodium lamps are excluded because a consensus for proper testing methods could not be reached. This Guide replaces the previous edition last published in 1981. See also LM-10, IESNA Approved Method for Photometric Testing of Outdoor Fluorescent Luminaires.