Vehicle Lighting, Signaling & Visibility

When your lights must be on

Your lights must be on between dusk and dawn. That daylight rule extends further, too: any time something cuts your visibility down to about 200 metres or less — a downpour, thick fog, falling snow, a tunnel — the lights go on regardless of the hour. Car drivers aren't legally obliged to keep dipped headlights burning around the clock, though it's a sensible habit; riders of motorcycles and mopeds don't get that choice — for them, the dipped beam stays lit non-stop, day and night.

Dipped beam versus full beam

Full beam has no place near a train or a vessel, nor on a road so continuously and well lit that you can already see clearly for about 100 metres ahead — switch to dipped beam in both cases. The same switch applies the moment you're following within roughly 50 metres of another vehicle, unless you're actually in the middle of overtaking it. And when a road user coming the other way flashes their lights at you, that's your cue to dip immediately rather than waiting for them to close the distance. Outside these specific triggers, the underlying principle covers everything else: never let your lights dazzle another road user.

Fog lights

Front fog lights aren't compulsory kit, and there's no rule forcing you to use them — but fog, snowfall, or heavy rain all justify switching them on. A rear fog light works differently: fog or snow only justify it once visibility has actually dropped to around 100 metres or less, while heavy rain justifies it regardless of how far you can see. Whatever the trigger, switch it back off the moment conditions improve — left on in ordinary visibility, it does nothing but dazzle and distract the driver behind you.

Hazard warning lights

Flick on every indicator at once whenever there's a genuine hazard to flag — a sudden queue of stopped traffic, a crash just around the bend. Doing this while you're still rolling is one of the rare times hazard lights are meant to be used on the move, giving the traffic behind a heads-up before it reaches whatever you've spotted. The same lights are called for once you've stopped: parked somewhere that's genuinely risky, sitting broken down on the roadside, or hooked up to something you're towing.

Keeping your lights in working order

A vehicle may only be driven on public roads if it fully meets its technical requirements, including working lights — this is a standing legal duty, not just something checked at a roadworthiness inspection. Reversing lights are a good example of how a light's use is tied to function: they may only illuminate while reverse gear is actually engaged, never at any other time.

Required lighting for night driving

• White or yellowish dipped headlights at the front.
• Red lights at the rear, plus red brake lights that light up more brightly when you brake.
• A white light illuminating the rear registration plate.
• Red reflectors at the rear.

Lighting a towed vehicle

Both the towing vehicle and the towed vehicle should run their hazard lights. With a rigid tow bar, the towed vehicle's own lights are normally enough as long as they still work. Towing with a flexible rope or strap instead needs a supplementary rear light bar attached to the towed vehicle so it remains clearly visible from behind.

Lights when stationary or parked

Come to a stop or park on the road itself or its verge somewhere between dusk and dawn — or really, whenever visibility sinks to about 200 metres or worse — and a pair of small lights becomes mandatory: one or two pale sidelights up front, one or two red ones at the back. Fog, snow, or a heavy downpour also give you the option, though never the obligation, of leaving your dipped headlights or your front-and-rear fog lights running while you're stopped.

Driving through a tunnel

Dip your headlights before the tunnel mouth swallows you, not after — visibility drops below 200 metres inside almost without exception. Sunglasses are worth losing beforehand too; keeping them on only makes the sudden plunge into darkness that much harder on your eyes.

The horn

Whatever horn came fitted from the factory is the only one you're allowed to sound, and every blast should be short. By day, a quick sound is fair game anywhere — inside or outside a built-up area — to head off a collision or catch someone's attention, and outside a built-up area specifically, it also doubles as your signal that you're about to pass the driver ahead. Once night falls, though, the horn is off-limits except for a danger that's genuinely about to happen; for anything less urgent after dark, flash your headlights instead.