Signalling means sending a message to another road user, perhaps by:
- raising or waving your arms or hands (commonly used by cyclists and police officers directing traffic)
- sounding horns or bells (used by all vehicles)
- lighting coloured lights (mostly motor vehicles, but sometimes cyclists too)
- shouting or hollering (mostly by cyclists and pedestrians)
Signals are also sets of lights you find on the road to control the flow of traffic, including traffic lights at junctions, lights at pedestrian or cycle crossings, and lights at level crossings (railroad crossings). Road markings and signs used for navigation, and signs giving instructions such as to "Give way" or go a certain speed, are not usually classed as signals.