An emergency vehicle signal light adapted to be mounted on an emergency vehicle. A light source emits visible light for illuminating a reflector. A light pipe having one end associated with the light source has its second end associated with a diverter for diverting substantially all light transmitted by the light pipe toward the reflector. The reflector is adapted to reflect the diverted light transmitted by the light pipe for observance by an observer remote from the emergency vehicle. A motion driver may be provided for rotating or oscillating the reflector about the diverter. As a result, an observer is adapted to observe discrete flashes of light resulting from flashing, rotation or oscillation, each flash corresponding to diverted reflected light forming a beam. For oscillating or rotating modules, the beam traverses across the position of the observer in response to the rotational or oscillatory motion. Alternatively, such modules may be used as part of a light bar. Alternatively, the modules may be stationary flashing modules which are flush mounted on the perimeter of an emergency vehicle.