On this day in 1923, inventor Garret Morgan was awarded the first U.S. patent for a three-position traffic signal. The Morgan traffic signal improved safety for motorists and pedestrians thanks to the third position all-directional stop, which halted traffic before resuming movement on one road. The signal could also be positioned at half-mast when traffic was low, altering motorists to proceed with caution, similar an intersection with flashing red or yellow lights today. Source: U.S. DOT Federal Highway Administration
