Note: This is an encore post from 2005 and originally appeared on the 1947project.

Adopted across the country and lampooned by Woody Allen, Los Angeles’ right turn on a red light was born in obscurity. Although the city used traffic semaphores (mechanical devices with metal arms reading “STOP” and “GO” that swung out of the signal—just like in the old cartoons and the opening of “Double Indemnity”) instead of lights, the right turn on red was in effect as early as 1939, when the City Council sought to ban them.

The state Legislature banned the right turn on red in 1945, but because cities were allowed to post exceptions, three survived: Mission Road at Macy Street and Sunset Boulevard at Castellar Street (now Hill Street), both downtown; and at Ventura and Lankershim Boulevards in the Valley.

Restored in 1947, the right turn on red remains the birthright of all L.A. motorists.

Bonus factoids: The city experimented with synchronized signals in 1922 to ease traffic. The length of a stop was cut from 45 seconds to 30.

“The traffic situation is Los Angeles’ single biggest problem,” The Times said — in 1924.