The marker boards should be red and white. They must be kept clean and independently lit at night and in poor visibility, so that other road users can see them.

If your vehicle is involved in a traffic incident, you must stop. Follow the guidance set out in The Highway Code if there's injury or damage to any other person, vehicle or property.

The horn shouldn't be used between 11.30 pm and 7.00 am in a built-up area. The only exception is when another road user is unaware of you and poses a danger.

The usual advice is to leave a minimum time gap of two seconds, but on wet roads you should leave at least double that time. Always take the road and weather conditions into account when you're driving.

The priority when dealing with an unconscious person is to make sure they have a clear airway and can breathe. Stay with the casualty and make sure someone rings for an ambulance.

The handling of a six-wheeled bus or coach is not much different from that of a two-axle vehicle, except that punctures can be more difficult to detect.

When a warning light or device indicating a loss of brake pressure comes on, you must stop safely and get the fault put right immediately. The safety of you, your load, your passengers and all other road users is at risk.

If you're taking medicine or drugs prescribed by your doctor, check that they won't affect your driving. If you forget to ask when you visit the surgery, check with your pharmacist.

This sign is placed on sections of road where overtaking would be dangerous. There'll often be a plate underneath the sign, telling you how far the restriction extends. You mustn't overtake until you pass another sign cancelling the restriction.

Solid white lines are used where it would be dangerous to overtake. If the solid line is on your side of the road, you may cross it to pass a stationary vehicle, or to overtake a pedal cycle, horse or road-maintenance vehicle that's travelling at 10 mph or less. You may also cross the solid line to enter premises or a side road.

If convicted, the current fine for each illegal immigrant brought into the UK is £2000. This fine can be imposed on each responsible person; this includes the vehicle driver, owner and hirer.

When you're being overtaken, the other driver has to decide when it's safe to complete the manoeuvre. Don't give an unofficial signal, however well intended. There may be a hazard you're unable to see from your position.

You must be able to stop safely in the distance that you can see to be clear ahead. This will be the distance illuminated by your headlights or by street lights and will generally be less than you can see in daylight.

A warning-lights check is sometimes performed automatically when the ignition is switched on. However, you may need to do this manually by operating a separate check switch. Never start a journey without carrying out this check. If there's a problem, have it repaired before you set off.

If you're involved in an incident in a tunnel, be aware of the danger this can cause to other traffic. You should immediately switch on your hazard warning lights and switch off your engine.

Always be aware of your limited vision around your vehicle, due to its size and shape. Never move off without checking along the nearside of your vehicle. You should be aware of the possibility of cyclists and motorcyclists getting trapped between your vehicle and the kerb.

Smart motorways are intended to reduce congestion and make journey times more reliable. In these areas, the hard shoulder may be used as a running lane to ease congestion at peak times or when an incident occurs. The variable speed limits shown in red circles are mandatory and help to keep traffic flowing at a steady speed.

The 'stop' sign is the only road sign that's octagonal. This is so that it can be recognised and obeyed even if it's obscured (for example, by snow).

Too much oil in an engine can be just as bad as too little. Overfilling an engine can create excess pressure, cause oil leakage through seals and result in expensive damage.

There's no way of knowing how deep the snow could be ahead. If you overtake and then become stuck in the snow, you may cause problems for the snow plough, particularly if you block the road.

Make certain that your filler caps are properly closed, so that you don't spill fuel as you drive along the road.

Always think of your own and others' physical safety before lifting any heavy object. Plan the lift and move any other items out of the way. Decide whether you need assistance.

When an emergency arises, pull onto the hard shoulder and use the emergency telephone to report your problem. You'll be connected to an operator, who will put you through to a breakdown service. Never cross the carriageway or a slip road to use a telephone.

You must obey these signs even if there appear to be no problems ahead.

Always check carefully for cyclists when emerging from a junction. Bicycles, being much narrower than any other vehicle, can be quite difficult to see.

Goods vehicles exceeding 2500 kg laden weight must always have their parking lights switched on when they're parked on the road at night. This includes parking in lay-bys: other drivers entering the lay-by must be able to see the vehicle.

Some weight restrictions apply to heavy goods vehicles only and not to passenger-carrying vehicles. Look for a plate beneath a restriction sign that indicates this. Road signs show weight restrictions in various ways. You should make yourself familiar with all of them, so that you're in no doubt about their meaning and relevance.

Leaving the filler cap off, or not properly securing it, could result in a spillage of diesel onto the road. Because diesel is slippery, this would be a major hazard, so make sure to correctly secure the filler cap after use.

If any vehicle displaying a warning symbol is involved in an incident, the consequences could be serious. The emergency services need to be aware of how a dangerous or hazardous material will behave in different situations; for example, when it's wet.