A traffic signal made up of a conventional stop and go configuration of lamps and switching means with an improved lamp control and improved lamps. The lamps are of the incandescent type, preferably having two filaments. The filaments are connected to a source of electrical current. The current is supplied...http://www.google.com.au/patents/US4799060?utm_source=gb-gplus-sharePatent US4799060 - Traffic signal
