who invented the 4 way automatic traffic light
William Potts (inventor) The first four-way traffic signal tower in the world was located at the Woodward and Michigan Avenue intersection in October 1920. The tower was manually operated and had 12 lamps, three in each direction. In December 1920, signals were added along Woodward Avenue at Grand River, State, Fort and Congress, but all were controlled from the manual tower at Woodward and Michigan.
Thomas Edison Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman, who has been described as America's greatest inventor.[1] He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and the long-lasting, practical electric light bulb. Dubbed "The Wizard of Menlo Park",[2] he was one of the first inventors to apply the principles of mass production and large-scale teamwork to the process of invention, and because of that, he is often credited with the creation of the first industrial research laboratory.[3]