Who invented the three-position traffic signal, patented in 1923?

Garrett Morgan invented the three-position traffic signal, which he patented in 1923.

Morgan’s design added a warning position between “stop” and “go.” Earlier two-position signals could change directly from allowing traffic to stopping it, leaving vehicles and pedestrians little time to clear an intersection. Morgan’s intermediate signal created a safer transition.

He received U.S. Patent 1,475,024 for the traffic signal on November 20, 1923. The device used a T-shaped pole with a rotating sign that displayed “stop,” “go,” or an all-direction stop. Morgan later sold the rights to General Electric.

Morgan was an African American inventor and entrepreneur from Kentucky who also developed an improved sewing-machine attachment and a smoke hood, sometimes called a safety hood. His signal was not the first traffic signal in history, and modern lights use electric coloured lamps rather than his rotating sign. Its lasting importance was the introduction of the familiar three-stage traffic-control concept.