Motor vehicles over 7500 kg maximum authorised mass (MAM) and trailers over 3500 kg MAM should have these markings fitted to the rear of the vehicle/trailer.

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.

It's essential to know the height of your vehicle before setting off. This should be clearly marked, usually in the cab, and visible from the driving position. Look out for restrictions that you may not have seen on a map - they may be temporary.

Be aware of, and obey, all speed limits. On a motorway, any lorry that's articulated, towing a trailer, or over 7.5 tonnes mustn't exceed 60 mph (96 km/h).

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.

A triangular sign is a warning sign. Knowing this, you can prepare for the hazard ahead.

Look for and obey traffic signs. Disobeying or not seeing a sign could be dangerous. It may also be an offence for which you could be prosecuted.

Children getting off the bus will be hidden from your view, and they may not be able to see you. Even if they can see you, they may have poor judgement of danger. You should drive slowly as you pass the bus and be ready to stop.

When moving a load, make sure you don't have to bend down or stretch up to reach the handles. Also, try to push rather than pull, so you can see where you're going.

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.

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.

Always be concerned for the safety of other road users. Be aware of the various factors and situations where you may have to take action to keep more vulnerable road users safe.

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.

As the lubricating oil is pumped around the engine, it collects tiny fragments of metal from the moving parts. The oil filter is designed to remove these fragments. Most filters are designed to be replaced at service intervals.

When the lights turn to green, you may drive on, but only if the crossing is clear. You should wait for any pedestrians to finish crossing, regardless of their age. Allow them to cross the road at their own pace; don't try to hurry them in any way.

The red emergency line is common to both two-line and three-line braking systems. Always set the parking brake before disconnecting any brake line.

Don't continue to drive if you feel the onset of tiredness. Find a safe place to stop for a rest. Walking around in the fresh air during your break will help but it's no substitute for adequate rest.

Engaging the diff-lock means that the driven wheels are locked together. This reduces the likelihood of wheel spin. Remember to switch off the diff-lock as soon as you're on firm ground again, otherwise you could damage the transmission.

When braking a vehicle carrying a liquid load, it's important to apply even pressure on the brake pedal. Don't relax the pedal pressure until the vehicle has stopped. Secure the vehicle with the parking brake before releasing the footbrake; this will minimise the risk of unintentional movement of the vehicle caused by 'surge' from the liquid load.

You should take precautions against dropping mud on the road, because it's a hazard to other road users. It's also an offence for which you could be prosecuted.

Every year, there are hundreds of incidents in the UK where vehicles hit railway or motorway bridges. Most involve buses, coaches and lorries. Make sure your route doesn't take you under a bridge that's too low for your vehicle. If you hit a bridge, you'll be putting yourself and any passengers at risk, and you could cause a major disruption to road and rail transport.

The spray-suppression equipment helps to prevent water from being thrown up and causing reduced visibility, for you and other drivers. Driving at a reduced speed in wet conditions will also help to reduce the amount of water thrown up by your vehicle's tyres.

It's very important to know the correct fire extinguisher to use. They'll carry a coloured label or badge telling you their contents. Make sure you learn which extinguisher is which, as using the wrong one could be dangerous and may spread the fire further. For example, you should never use a water extinguisher on burning oil.

To help a casualty who isn't breathing, you should remove any obstructions from their mouth and tilt their head back slightly. These actions will help to keep their airway clear and maintain the correct position if mouth-to-mouth resuscitation is required.

It's your responsibility to make sure that the vehicle's load is spread evenly, to avoid overloading individual axles. Overloading carries severe penalties for the driver and operator.

When someone ahead of you switches on their hazard warning lights, it means that they've spotted a hazard that you may not be able to see yet. Slow down and be ready to stop if necessary.

To comply with the law, all lights must be in good working order, even in daylight when they're not being used. Before you set out, make sure that everything is working and get any faulty lights fixed. You may need to use your headlights or other lights if you're delayed or find yourself driving in conditions of reduced visibility.

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.

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.

Hitting the kerb at speed can split the tyre or put the steering and suspension geometry out of alignment. Have it checked as soon as possible. A sudden puncture in a front tyre could result in a loss of steering control and a serious crash.