is a form of rotary traffic signal
that was designed by Charles Marshall in 1936. It consists of two rotors pointing at coloured sections that denoted whether traffic in either direction should proceed, prepare, or stop. Variations exist for pedestrian crossings
with additional text instructing crossers to "Walk" or "Don't Walk". The last Marshalite to exist before they were removed in the 1970s was along the Nepean Highway
, in Victoria
With the Marshalite, drivers have a clear indication of when the signals will change, though the Marshalite system cannot cope with changing traffic loads.