SALT LAKE CITY (AP) — Pedestrians, horses, trolleys — and a growing fleet of automobiles — clogged early 20th Century streets in America. Travel was slow, navigation dangerous, and traffic cops stood amid the chaos at their own peril.

Enter Lester Farnsworth Wire, the dean of Salt Lake City’s inaugural traffic squad and arguably the inventor of the world’s first electric traffic light in 1912: A birdhouse-like box with red and green bulbs on each side to signal stop and go to travelers.