The Marshalite 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, Australia. A similar system was proposed in Germany in the 1950s, and while shown in publications, the signal does not seem to have been put into use.
With the Marshalite, drivers have a clear indication of when the signals will change though the exact point of change is not clear.
Aesthetically wonderful? Absolutely. Practical? Probably not.