Weather conditions

The advice given in section 12 is even more important on a motorway.

Wet weather

Visibility can be made worse because, at higher speeds, vehicles (especially large ones)

throw up more spray. So

• use your headlights to help other drivers see you. Don’t use rear fog lights unless visibility is less than 100 metres (328 feet)
• always reduce your speed when conditions are poor. Driving is safer at lower speeds
• adjust your speed to suit the conditions and leave larger separation distances, at least double the normal gap.

Ice or frost

Ice or frost on the road can seriously affect your handling of the vehicle.

Try to anticipate the road surface conditions. If your steering feels light, it’s an indication that there may be frost or ice. Be very gentle with your use of the controls.

Allow up to 10 times the normal distance for braking.

Side winds

Wind is another motorway hazard.

Wind can affect your steering. If it’s coming from the left on an exposed stretch of motorway, be especially careful. A sudden gust as you pass a large vehicle, or come out from under the shelter of a bridge or embankment, can send you swerving to the right.

In strong wind, drivers of high-sided vehicles or those towing caravans may experience difficulties. Motorcyclists can also be affected by strong side winds. Allow for this when overtaking these vehicles.

Fog

Driving on the motorway when the weather is foggy can be particularly hazardous.

If there’s fog on the motorway, you must be able to stop well within the distance you can see to be clear.

• Use dipped headlights.
• Check your mirrors and slow down; fog affects both visibility and judgement of speed and distance.
• Check your speedometer and leave plenty of space between your vehicle and the vehicle ahead.

Fog can drift quickly and is often patchy.

If a motorway warning sign shows ‘FOG’

• be prepared
• reduce your speed in good time.

Multiple pile-ups can happen in foggy conditions. They’re usually caused by drivers who are

• travelling too fast
• driving too close to the vehicle in front
• assuming there’s nothing in the fog ahead.

If there’s fog

• switch on your fog lights if visibility drops below 100 metres (328 feet)
• be prepared to leave the motorway • be on the alert for incidents ahead
• watch out for emergency vehicles coming up behind, possibly on the hard shoulder.