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.

Adding a fourth light to traffic signals -- in addition to red, green and yellow -- would shorten wait times at street corners for pedestrians, as well as improve traffic flow for both autonomous ...

Blue lights are being used at traffic signals in some areas of the United States. These lights do not provide instructions to ...