Lester Farnsworth Wire (September 3, 1887 – April 14, 1958) was credited with the invention of the electric traffic light in 1912 in Salt Lake City.
Wire worked as a detective for the Salt Lake City police force.
The original traffic light, based on a semaphore system, had been invented in London in 1868 by John Peake Knight but had not been a success.
The earliest known patent for a traffic light in the United States was U.S.Patent # 1,251,666 issued January 1, 1918, to J.B.