a signalling device positioned at a road intersection or pedestrian crossing to indicate when it may be safe to drive, ride or walk, using a universal colour code
Traffic lights are sets of red, amber, and green lights at the places where roads meet. They control the traffic by signalling when vehicles have to stop and when they can go. Traffic lights can also be referred to as a traffic light. A road signal for directing vehicular traffic by means of colored lights, typically red for stop, green for go, and yellow for proceed with caution. Also called stoplight, traffic signal