Rules of the road

Night & Bad Weather

Reduced visibility, headlight use, and driving in rain, snow, and fog.

Switch to low beams within 150 metres of an oncoming vehicle or 60 metres of one you are following, and treat both fog and whiteouts as a reason to pull completely off the road if visibility drops far enough.

Night and bad-weather driving both come down to the same trade: you have less usable information about the road, so you owe it more time, more space, and less speed.

Key facts

You must use low-beam headlights within 150 metres of an oncoming vehicle, or within 60 metres of a vehicle you are following.
Black ice looks like ordinary black, shiny asphalt rather than the grey-white colour of typical winter road surfaces, which is exactly why it is dangerous.

Use headlights correctly at night

Switch to low beams within 150 metres of an oncoming vehicle or within 60 metres of a vehicle you are following, so you do not blind the driver ahead of or approaching you. On a country road, switch to low beams at curves and hilltops even without a visible oncoming vehicle, since one can appear suddenly.

Never drive faster than your headlights let you see and stop safely; this is called overdriving your headlights, and reflective signs in the distance can make the road look more visible than it actually is beyond your headlight range.

Handle fog, rain, and whiteouts

In fog, use low beams rather than high beams, since high beams reflect off the moisture and reduce your own visibility further. Turn on fog lights if your vehicle has them, increase your following distance significantly, and avoid passing or changing lanes.

In heavy rain, watch for hydroplaning, where your tires ride on top of standing water instead of gripping the road; reduce speed and increase your following distance to compensate. If visibility drops close to zero in fog or a whiteout, pull completely off the road into a safe parking area and turn on your emergency flashers rather than continuing to creep forward.

Recognize and respond to snow and ice

Do not use cruise control on snow-covered roads, since it can prevent you from noticing a loss of traction as quickly as you would while manually controlling your speed. Slow down on rutted, snowy roads and avoid sudden steering, braking, or accelerating, any of which can trigger a skid.

Black ice appears as ordinary black, shiny asphalt rather than the grey-white colour typical of a winter road surface, which is exactly what makes it so easy to miss; treat any unusually dark, glossy patch of road in freezing conditions with suspicion.

Common mistakes

Leaving high beams on within 150 metres of an oncoming vehicle.
Using high beams in fog instead of low beams.
Using cruise control on a snow-covered road.
Assuming a shiny, dark patch of road in freezing weather is simply wet rather than black ice.