Vehicle lighting, signalling and visibility requirements
Lights
A tractor used on the road needs working headlights, rear lights, brake lights, indicators and rear reflectors. Outside built-up areas in daytime, use low-beam headlights or approved daytime running lights. At night or in poor visibility, use low beam; do not use work lights on the road if they dazzle others. A trailer or implement must show its own rear lights and reflectors if it obscures the tractor lights. Clean mud, dust and crop debris from lamps and plates before entering the road.
Signalling
Signal before moving off, turning, changing lane, overtaking or stopping. Cancel the indicator after the manoeuvre. If an indicator fails, use the hand signal required by the code and repair the fault before continuing. A tractor with a wide implement may need additional marking so other drivers understand its width.
Visibility
Keep mirrors clean and adjusted. Check blind spots before moving a wide load. In rain, mud or fog, slow down and increase the gap. A slow-moving vehicle sign or amber beacon may be required or permitted for certain agricultural work; it does not give priority. Do not rely on others to see you.
Worked example
A tractor leaves a muddy field at dusk. The rear lights are coated in mud and the trailer has no separate lights. Reasoning: the tractor must not enter the road until the lamps and plates are clean and the trailer lights work. At dusk, low beam is needed; if the trailer hides the tractor lamps, the trailer must carry its own rear lights and reflectors.
Traps
Using work lights as headlights; forgetting trailer lights; driving with mud-covered lamps; and signalling late or not cancelling.