Rain, fog, smoke and floods

By the end of this topic you can

• You can adjust your speed and following distance for wet roads.
• You can use headlights, fog lights and hazard lights correctly in poor visibility.
• You can explain why floodwater is so dangerous and what to do instead.
• You can decide when to pull over and wait for conditions to improve.

What you need to know and understand

• On wet roads your car takes longer to stop, so increase your gap. The WA handbook suggests at least doubling it.
• Turn on your headlights when it rains if they do not come on automatically.
• In fog or smoke, use low beam. High beam reflects off the fog and makes it harder to see.
• Fog lights may only be used in fog, heavy rain or other conditions that limit vision, such as smoke or dust, and must be switched off when it clears.
• Hazard lights may be used in thick fog or very heavy rain.
• Floodwater can hide damaged roads and debris, and its depth and speed are hard to judge. It is safer to turn around.

Wet roads

Rain mixes with oil and dust on the road, especially after a dry spell, and makes the surface slippery. Brake gently and earlier, steer smoothly and avoid sudden acceleration. Most skids are caused by harsh braking, harsh acceleration or steering too sharply for the conditions.

Keep your wipers in good condition and use your air conditioner or demister to stop the windscreen fogging up. Watch for pedestrians and cyclists, who are harder to see in the rain.

Fog, smoke and dust

• Slow down to a speed where you can stop within the distance you can see.
• Use low beam headlights, not high beam.
• Use fog lights only while visibility is reduced, and turn them off as soon as it improves.
• Leave a much bigger gap to the vehicle in front.
• If visibility becomes very poor, pull well off the road in a safe place and wait.
• Before you set out, check warnings for storms, bushfires, dust storms and heavy fog, and change your plans if needed.

Floodwater: turn around

Never drive into floodwater. You cannot tell how deep or fast it is, the road underneath may be washed away, and the level can rise quickly. A car can lose grip and float in surprisingly shallow moving water.

Warning signs such as Road subject to flooding and depth indicator posts tell you a road can go under water. If water is over the road, find another route or wait until the road is clear. Turning around costs you time; driving in can cost your life.

1. Stop well before the water.
2. Check behind you, then turn around safely.
3. Choose another route or wait somewhere safe.
4. Listen to local radio or emergency warnings for road closures.

Common mistakes

• Driving at the posted speed limit in heavy rain. The limit is for good conditions; slow down.
• Using high beam in fog. Low beam lets you see more.
• Leaving fog lights on after the fog clears. That is an offence and dazzles other drivers.
• Trying to cross a flooded road because other cars did. Every crossing is a gamble; turn around.
• Following too closely in spray. Double your gap so you have time to stop.

Test yourself: Rain, fog, smoke and floods

Answer each question, then read the explanation. Questions come in a random order each time.

Go deeper

• Driving in Rain, Fog, Smoke and Floods in Australia