How robot cars make themselves understood

Cieler has a suggestion for the specific design: A turquoise band of light around the vehicle indicates that it is in autonomous mode. When it flashes, it tells you to stop and yield or give way to the other. Turquoise because, according to Cieler, the color, unlike blue or yellow flashing lights, has not yet been used in traffic. And because it does not imply any instructions – such as a red traffic light or a green that suggests free driving.