One hundred years ago today, just a few kilometers from where I'm now sitting, Cleveland installed the first electric traffic signal at corner of Euclid and East 105th:
Various competing claims exist as to who was responsible for the world's first traffic signal. A device installed in London in 1868 featured two semaphore arms that extended horizontally to signal "stop" and at a 45-degree angle to signal "caution." In 1912, a Salt Lake City, Utah, police officer named Lester Wire mounted a handmade wooden box with colored red and green lights on a pole, with the wires attached to overhead trolley and light wires. Most prominently, the inventor Garrett Morgan has been given credit for having invented the traffic signal based on his T-shaped design, patented in 1923 and later reportedly sold to General Electric.
Despite Morgan's greater visibility, the system installed in Cleveland on August 5, 1914, is widely regarded as the first electric traffic signal. Based on a design by James Hoge, who received U.S. patent 1,251,666 for his "Municipal Traffic Control System" in 1918, it consisted of four pairs of red and green lights that served as stop-go indicators, each mounted on a corner post. Wired to a manually operated switch inside a control booth, the system was configured so that conflicting signals were impossible. According to an article in The Motorist, published by the Cleveland Automobile Club in August 1914: "This system is, perhaps, destined to revolutionize the handling of traffic in congested city streets and should be seriously considered by traffic committees for general adoption."
Only 100 years later, the traffic lights have minds of their own.