The safety mask isn't Morgan's only invention. Another one, introduced in 1923, was the traffic light that incorporated the potentially life-saving cautionary signal between stop and go.

A drawing showing the first street crossing ... the first design of the traffic light had a rough start. A gas leak from the supply pipe beneath it triggered an explosion in the traffic light ...

New research shows that AI in cars might warrant a new, four-light traffic signal that is more efficient. Getty Images/iStockphoto Surely this will complicate the game of red light, green light.

What do you think of a fourth traffic light color being added to traffic signals for self-driving vehicles to help control traffic flow? I get that one day a bunch of connected autonomous cars may ...

The signs said "stop" and "proceed." The first electric traffic light using red and green lights was invented in 1912 by Lester Farnsworth Wire, a police officer in Salt Lake City, Utah ...