The control for changing to the dipped-beam must switch off all main-beam headlamps simultaneously, whereas the dipped-beams may remain switched on at the same time as the main beam.
Driving lamps shall be switched off and replaced by passing lamps:
(a) In built-up areas where the road is adequately lighted and outside built-up areas where the carriageway is continuously lighted and the lighting is sufficient to enable the driver to see clearly for an adequate distance and to enable other road-users to see the vehicle far enough away;
(b) When a driver is about to pass another vehicle, so as to prevent dazzle far enough away to enable the driver of the other vehicle to proceed easily and without danger; (c) In any other circumstances in which it is necessary to avoid dazzling other road-users or the users of a waterway or railway running alongside the road.