Look out for variable-message warning signs telling you about

• lane closures
• speed limits
• hazards.

When you're clear of the restriction, you'll see a sign telling you that it has ended.

If you're trying to resuscitate a casualty, don't give up until medical help arrives. Never assume that someone's dead. People who aren't breathing can survive longer than you may imagine when given chest compressions and mouth-to-mouth resuscitation.

Driving at higher speeds and for longer periods, such as on motorways, can cause your tyres to overheat and disintegrate. You should make a point of checking them when you stop for a break.

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

Suspension faults may result in road damage. Road-friendly suspension reduces the impact on the environment, the road surface and under-road services.

If you try to overtake another vehicle and realise that you're unable to complete the manoeuvre, ease off the accelerator and drop back behind the vehicle. If the vehicle you're trying to overtake is large, then it will take a long time to pass. You should assess whether you have the time and power to complete the manoeuvre before you try to overtake.

Hazardous substances in transit are readily identified by a diamond-shaped warning label. This label carries other information to identify the type of hazard more specifically, such as

• flammable gas
• toxic gas
• corrosive agents.

These are just some of the types of hazard encountered. Strict regulations apply to the storage and carriage of these goods. All drivers of this type of load must receive specific certificated training.

The risk of fire will be reduced if all fuel supplies are switched off. However, don't put yourself or your passengers at any risk. If there's a fire, call the fire service.

Look out for signs above your lane or on the central reservation. These will give you importantn information or warnings about the road ahead. To allow for the high speed of motorway traffic, these signs may light up some distance from any hazard. Don't ignore the signs just because the road looks clear to you.

If you stop for pedestrians and they don't start to cross, be patient. Don't wave them across or sound your horn. This could be dangerous if the driver of an approaching vehicle isn't aware of them. The driver may not have seen or heard your signal, making it very dangerous for the pedestrians to start to cross.

When starting an engine fitted with an engine management system, you don't need to press the accelerator, because the engine management system automatically regulates the fuel/air supply. Using the accelerator at start-up wastes fuel, causes increased engine noise and is harmful to the environment.

A bus equipped with a speed limiter must also be fitted with a plate showing the speed setting. This must be fitted in an obvious position, where it can be clearly seen.

Too much weight on an axle can reduce braking efficiency and cause brake fade. As well as being dangerous, exceeding the axle weight limit is an offence that can result in prosecution.

Before entering a tunnel, you should switch on your dipped headlights; these help you to see and be seen. In many tunnels, using headlights is a legal requirement. You should also remove your sunglasses before you drive into a tunnel.

You should remain in the left-hand lane unless you're overtaking other vehicles. Don't be inconsiderate and stay in the centre lane or other overtaking lanes when you've finished overtaking.

When changing or fitting new tyres, consider buying energy-saving tyres. These have a reduced rolling resistance and improved efficiency, which helps to keep fuel costs down.

Stopping where you see this sign is likely to cause an obstruction, which could lead to traffic delays. Obeying the sign will help keep the traffic flowing.

If the brake pedal is hard to press, this could mean a loss of vacuum or a fault in the vacuum pump. You shouldn't drive the vehicle until the fault has been repaired.

A sleeper cab can create extra blind spots. Look out for vehicles just to the rear offside and nearside of your cab - they could soon become hidden in your blind spots.

The forces that act on your vehicle if you brake while cornering can lead to instability and may cause trailer swing. You should try to plan ahead so that you brake smoothly and in good time as you approach a bend.

When transporting livestock, it's important to limit the amount of space they have to move around. If you allow them to move around freely, it could increase the risk of injury to the animals. It will also affect the stability of the vehicle when braking and cornering, and could even cause the vehicle to tip over.

In very cold weather, moisture in the storage tanks can freeze. Ice can form in the pipes and this will result in loss of pressure, which could cause brake failure. Make sure that you drain the tanks daily as part of a routine. Most modern vehicles are fitted with automatic bleed valves. Check that they're working properly and that air-drying systems are effective.

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

On motorways, be especially careful when driving over bridges and viaducts. The road here is exposed and in windy weather there's a risk of strong side wind, which may blow you off course or even blow your vehicle over. In severe windy weather, these routes are often closed to drivers of high-sided vehicles.

If your vehicle touches bells suspended over the road, they'll obviously ring. This will warn you that your vehicle exceeds the safe travelling height beneath electrified overhead cables ahead. You must stop immediately and either find another route or take advice.

You'll need to identify the sign in time, so that you can select an appropriate gear.

If you apply for a PCV or LGV licence, you must demonstrate that your eyesight is good enough to drive safely. DVLA (or DVA in Northern Ireland) can give you specific information about this. It's your responsibility to tell DVLA or DVA if your eyesight changes or you can't meet the requirements.

Jack-knifing occurs when the tractor unit is pushed by the semi-trailer pivoting around the coupling (fifth wheel). This is more likely to occur with an unladen vehicle.

Misuse of drugs and/or alcohol may lead to the withdrawal of your driving licence. Future insurance premiums will probably increase as well.

Faulty power steering will make your steering wheel very difficult or almost impossible to turn. Continuing to drive could cause danger to you and other road users. You should park safely and get help.

Roadworks can involve complex lane layouts. Reflective green-and-yellow fluorescent studs are used to separate the lanes in a contraflow traffic system. As you approach roadworks, look for traffic signs giving you advance information, which may relate to the size or type of vehicle you're driving.

The formula used to calculate the payload of a vehicle is the maximum authorised mass (MAM) minus the tare weight. The tare weight is the total weight of the vehicle, including the crew and extra equipment.

As a local-service bus driver, you may use the bus lane at any time. The restrictions apply to other road users, to keep the lane clear for you at peak times. Don't be tempted to speed when driving up the inside of slow-moving or stationary traffic. Be alert for pedestrians who may be trying to cross the road.

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.

Keeping your vehicle's tyres in good condition will give them a good grip on the road and will improve the vehicle's overall stability. Each tyre must have at least the minimum legal depth of tread across three-quarters of its width. Renew tyres well before they wear to less than that.

As you approach the children, consider whether you need to sound the horn as a warning. Always check your nearside mirror as you pass any hazards on the left, so that you know when your vehicle is clear of the hazard.

Your head restraint should be adjusted so that, in the event of a collision, it protects your neck from whiplash injury.

Wet roads will increase the time it takes you to stop. Four seconds is the minimum gap you should leave on wet roads. This is double the gap you should normally keep from the vehicle in front on good, dry roads.

No motor vehicles are allowed past this sign. Although a motorcycle and car are shown, the restriction applies to all motor vehicles.

Never follow any road user too closely. This is particularly important when you're following scooter or motorcycle riders, or cyclists. They might brake or swerve suddenly; for example, to avoid a pothole on a road with a poor surface.

Check that the ground is firm and level before you uncouple the trailer. If you need to, place a heavy plank under the legs to distribute the weight and stop the legs sinking into the ground. Don't park illegally. Make sure that your unattended trailer isn't blocking access for others.

Always look out for road signs, but be especially aware of those that refer to large or heavy vehicles. Get into the habit of checking for signs at junctions. There might be an indication on the junction layout sign. Before you turn, make sure that the road you're using doesn't have any restrictions for the vehicle you're driving.

Never commit yourself to overtaking unless you're absolutely certain that you have the time and space to complete the manoeuvre safely. Don't take any risks that will endanger other road users.

Always have wheel nuts checked soon after their initial tightening. They should be tightened to the torque specified by the vehicle manufacturer.

When you drive too close to the kerb, there's a risk that your nearside mirror could strike the head of a pedestrian. Be aware of this hazard and, if you see pedestrians close to the road, make sure you leave them enough room.

The maximum permitted length of vehicle includes any trailer being towed. Make sure you know the total length of your vehicle.

Some vehicles are fitted with an audible warning that sounds when the vehicle is reversing. This is an effective way to warn pedestrians and other road users of a reversing vehicle, but it doesn't take away the need to use effective observation all around your vehicle before and while you're reversing. Don't use the device in built-up areas between 11.30 pm and 7.00 am. Have consideration for the residents and don't disturb them with excessive noise.

It's important to keep a safe distance from the vehicle in front at all times. This still applies in congested tunnels, even if you're moving very slowly or have stopped. If the vehicle in front breaks down, you may need room to manoeuvre past it.

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.

In congested tunnels, you should always obey the instructions given by variable message signs and tunnel officials. Listen out for radio announcements and observe the road signs and signals. Keep your distance from the vehicle in front.

Traffic behind that's returning from the right-hand lane is a hazard to be aware of before you move into the middle lane to overtake. Checking your blind spot can help you see these vehicles before you commit to changing lanes.

If it's possible, and you can do so without causing further danger, it's safer to drive a vehicle that's on fire out of a tunnel. The greatest danger in a tunnel fire is smoke and suffocation.

If you have to drive through a flood, do so with caution. Once out of the flood, you need to test your brakes to make sure they're working properly. To do this, check what's behind you, then drive in a low gear with the brakes gently applied.

Air suspension provides a smoother journey than traditional suspension and transmits less vibration to the road surface, under-road services and nearby structures, such as bridges. It's considered to be environmentally friendly because it reduces damage to the road network.

Endurance brakes or 'retarders' help to control a vehicle's speed. They operate by applying resistance to slow the vehicle without using the wheel brakes, so avoiding brake fade. The methods used include: increased engine braking, exhaust braking and transmission-mounted devices.

Short-wheelbase vehicles will bounce more noticeably than some long-wheelbase vehicles when empty. This can affect braking efficiency and all-round control.

Heavy braking can cause an articulated vehicle to become unstable and may even lead to jack-knifing; this is more likely to occur when the trailer is unladen.

These markings are found on the road outside schools. Don't stop or park on them, even to set down or pick up children. The markings are to make sure that drivers, riders and children have a clear view.

The amber light means stop. You may only go on if the light changes to amber after you've crossed the stop line or when you're so close to the line that stopping might cause a collision. The amber light is followed by the red light. You must wait behind the stop line until the green light shows.

A full category D licence entitles you to tow a trailer of up to 750 kg. If you wish to tow a trailer over 750 kg, you must pass an additional test.

Your tyres must be in good condition and properly inflated to the manufacturer's recommended pressure. Research has shown that the tyres most likely to fail are those that have been over-inflated.

Take the time to check where the blind spots are when driving a vehicle that's unfamiliar to you. Being aware of the limitations of your mirrors will help you take steps to prevent collisions. Always check the blind spots before changing direction. Frequent and proper use of the mirrors will help you to be aware of a vehicle moving into your blind spot.

A red cross above the hard shoulder means that it's closed as a running lane and should only be used for emergencies or breakdowns. At busy times, the hard shoulder may be used as a running lane; the red cross will then be replaced by a mandatory speed-limit sign.

If you see a vehicle with a green flashing light, it will be a doctor on an emergency call, so give way by pulling over and letting the vehicle pass. But don't just stop suddenly - choose a safe place as soon as you can to let the doctor's car pass safely.

A kingpin or drawbar lock is a visible and effective deterrent to thieves wishing to steal an unattended trailer.

If there's a bend just before a level crossing, you may not be able to see the level-crossing barriers or waiting traffic. These signs give you an early warning that you may find these hazards just around the bend

When you're driving on a smart motorway, speed limits will show above each lane. These limits are shown inside a red circle and must be obeyed. A red cross will usually appear above the hard shoulder. When the hard shoulder is being used as a running lane, an appropriate speed limit will be displayed instead.

When traffic is heavy, plan well ahead so that you don't block crossings. Leave them clear so that pedestrians can cross safely.

Continuous use of the brakes on a long downhill gradient can cause them to overheat and become ineffective. This is called brake fade. You should use a low gear to enable the engine's braking effect to help control your speed. Also use the vehicle's retarder, if fitted. As well as reducing the likelihood of brake fade, this helps to keep air pressure in the tanks.

When a tyre explodes, fragments are thrown over a wide area. This can create a serious hazard for other drivers. You should regularly check your tyres for cuts, damage and pressure. Frequent checks and proper maintenance can help prevent a blow-out.

Always use the MSM routine when you're approaching a hazard.
M - Mirrors: check the position of the traffic behind you..
S - Signal: signal your intention to slow down or change course in good time..
M - Manoeuvre: a manoeuvre is any change in position, from slowing or stopping the vehicle to turning off a busy road.

DVSA and the police carry out frequent roadside checks of commercial vehicles. Where serious defects are found, the vehicle is taken out of use until they're put right. Details of the prohibition are shared with the traffic commissioner.

If you're travelling on a motorway and your view ahead is poor, then you should reduce your speed. Leave at least four seconds between your vehicle and the one in front, and make sure that others can see you by using your dipped headlights.

In good dry conditions, you should leave a two-second gap between your vehicle and the one ahead. When the weather is bad, you'll have to keep a greater distance, because it will take you longer to stop. In wet weather it will take up to twice the distance; in icy weather this could increase to ten times as far.

At night, you can tell whether a vehicle is facing towards or away from you by the colour of its lights. Additionally, its brake lights or indicators can give you information about its direction and intentions. This information helps you to make safe driving decisions.

Vehicles that are used to carry children to and from school will be travelling at busy times of the day. Be prepared for a vehicle with this sign to make frequent stops. It might pick up or set down passengers in places other than normal bus stops.

It's a serious offence to drive without insurance. As well as an unlimited fine, you may be disqualified or given penalty points.

There's a particular risk when driving between 2 am and 7 am. This is when the 'body clock' is programmed for sleep in most people. There's another, smaller, dip between 2 pm and 4 pm. If you feel that tiredness is affecting your ability to drive, stop in a safe place and rest.

Moisture in the air condenses as the air pressure increases. This moisture can be transmitted around the braking system and is especially dangerous in cold weather. It can lead to ice forming and blocking the valves and pipes.

Major roadworks often cause complicated diversions for large vehicles. Drivers may be advised to follow a special symbol until the original road can be rejoined. Look for the yellow-and-black symbols in these shapes:

• square
• triangle
• diamond
• circle.

They'll often be shown with additional information and will help guide you around the diversion.

Roll-over' usually happens as a result of the inside rear wheels of an articulated vehicle starting to lift when the driver changes direction sharply. This tends to happen when a driver is changing direction to leave a roundabout. If the load moves during the change of direction, the vehicle is increasingly at risk of rolling over. The problem often involves vehicles carrying fluids in bulk.

If the engine contains too much oil, the moving parts can hit the oil surface, causing a loss of power or even damage to the engine. Excess pressure may damage oil seals, causing oil to leak onto the road, creating a slippery and dangerous road surface.

When emerging, if you can't see, don't go. Be aware that there could be an approaching cyclist or motorcyclist hidden by parked vehicles. Edge out very slowly, checking in all directions, and be ready to stop.

Overloading a vehicle is dangerous. Your stopping distance will increase, and your vehicle could become unstable and difficult to control. You'll need to work out the payload. Do this by taking away the kerbside weight from the maximum authorised mass (MAM). This will give you the maximum weight you can carry.

Being seated properly is very important when driving long distances. A poor driving position can quickly cause fatigue. You should make sure that you can reach all the controls comfortably.

The driver of a passenger-carrying vehicle needs to know the vehicle's limits. These include its weight, height, width and length, and its seating and standing capacity. The unladen weight should be displayed on the nearside of the vehicle.

If there's nothing embedded in the wound, you can control the blood loss by applying pressure to the wound and raising the leg if possible.

In cold weather, diesel fuel can solidify as it starts to freeze. This is known as waxing. Waxing prevents the fuel from flowing properly and this can stop the engine from running.

All drivers should play their part to protect the environment against traffic pollution. Make sure the vehicle you drive is properly maintained. Report any defects, such as excessive exhaust smoke, as soon as you can.

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.

A green flashing light on a vehicle means the driver or passenger is a doctor on an emergency call. Give way to them if it's safe to do so. Be aware that the vehicle may be travelling quickly or may stop suddenly.

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.

Tailgating' - travelling too close to the vehicle in front - is very dangerous, because it doesn't give you enough distance to stop safely. Leave at least a two-second gap in good conditions, and increase this to four seconds in wet weather.