To warn the driver that the road ahead may be obstructed; pedestrians, rescue teams, police or traffic officers may be present at the scene; and wreckage, injured people, animals or broken glass may be on the road surface.
Slow down immediately, look out for someone controlling the traffic and be ready to stop. If there is enough help or professional help on the scene, do not stop out of curiosity. Do not look at the collision scene or wreckage; concentrate on the route to be followed without driving over or into anything.
Where to expect it: On any road.
