Traffic Signal

Garrett Morgan, USA, patent 1,475,024 of 1923. The T-shaped signal that added a warning phase and saved streets.

Overview

Morgan, a Black Cleveland inventor of the gas mask Hood fame, patented a three-position traffic signal with a warning stance between stop and go. He sold rights to General Electric for 40,000 dollars, a rare straightforward win for an African-American inventor of the era. Earlier electric signals existed in London 1868 and Salt Lake 1912, but the caution phase was his addition. Railroads had used semaphores; his T-pole adapted them to streets. Every amber light owes him a nod.