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 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.

Sometimes other drivers or riders make a mistake. If this happens, try not to let it worry you. Don't react by sounding the horn, flashing your headlights or shouting at the other driver; it won't help the situation. A professional driver will remain calm and stay focused on their driving.

The full name of the CMR is the 'Convention on the Contract for the International Carriage of Goods by Road'. You'll need this document to transport goods internationally by road. Of the four copies required, the consignor, consignee and originator all have one copy, and the fourth travels with the vehicle.

If you're disqualified from driving because you were two-and-a-half times over the legal limit, you'll be classified as a high-risk offender. Before you can regain your licence, you'll have to satisfy the Driver and Vehicle Licensing Agency (DVLA) that you don't have an alcohol problem.

Where a motorway has a steep uphill gradient, slow-moving, large vehicles might get in the way of other traffic. An extra lane on the left may be provided for these slow-moving vehicles. It allows faster-moving traffic to flow more easily.

If you drive a vehicle carrying dangerous or hazardous material, you must make sure the correct symbol or mark is clearly visible.

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

The car is the most stable of the vehicles shown. However, all vehicles are affected by side wind and buffeting from larger vehicles. Be aware that your speed and road position could cause unnecessary turbulence when passing smaller vehicles.

It's a legal requirement that your tyres have at least the minimum permitted depth of tread and are in good condition before you start any journey. Make sure that you inspect them before setting off, and at regular intervals.

Remember that the buffeting caused by large vehicles can affect other road users, including

• cars towing caravans
• motorcyclists.

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.

Only overtake when it's safe to do so, and don't use the size of your vehicle to intimidate approaching traffic. When overtaking a cyclist, leave plenty of room and, before returning to the left, check in your nearside mirror to make sure you've passed them safely.

On a motorway, it's best to use a roadside emergency telephone so that the emergency services are able to locate you easily.

At motorway roadworks, some lanes may be narrower than normal and large vehicles may not be allowed to use those lanes. Look for weight-limit signs to check for any lanes that you can't use. Move to the appropriate lane in good time.

Air suspension reduces the pounding of the vehicle on an uneven road surface. This, in turn, reduces the vibrations transmitted to buildings and underground services along the route.

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

Driving at high speed on a wet motorway can throw up dense spray, making it very difficult for other drivers to see ahead. Driving more slowly reduces the amount of spray and this makes it safer for other drivers.

Be especially careful about moving casualties at the scene of an incident. Inexperienced handling of a casualty could cause more injury, or even prove to be fatal. Only move casualties if they're in danger; for example, from fire.

Demountable bodies have legs that can be lowered so that the carrier vehicle can be driven out from underneath the body. This has an advantage over ISO containers, which require some form of crane or lift to remove the container from the trailer.

If you're using a vehicle equipped with an analogue tachograph, you'll need at least one chart for every 24 hours. Your employer should supply you with enough tachograph charts for your entire journey.

Warn other traffic of the incident, without putting yourself or others at risk. Once the danger of further collisions is dealt with, call the emergency services. While you're waiting for them to arrive, keeping casualties or witnesses calm is important, but never offer a cigarette because of the risk of fire.

The hours of operation of Red Routes vary from one area to another. As a rule, you mustn't stop on a Red Route, but there may be special marked boxes where loading and unloading can be carried out at certain times. Look out for signs giving information about the restrictions in place.

Today, all water-cooled engines use a mixture of water and anti-freeze to make up the coolant. As well as helping to keep the engine at its correct operating temperature, the anti-freeze acts as a corrosion inhibitor to prolong the life of the cooling system.

Most diesel engines have glow plugs to preheat the combustion chambers, so helping the engine to start when it's cold. When the ignition is switched on, the preheat warning lamp will show and the glow-plugs will rapidly heat up. In cold weather, the starter should only be operated when the glow plugs reach operating temperature and the warning light goes out.

Your tachograph chart is a legal document; it's a record of your work covering a rolling 24-hour period. Drivers who break the rules are subject to heavy fines and could lose their vocational licence. Altering your tachograph chart with intent to deceive is against the law and could lead to a prison sentence. Similar penalties exist for those who permit such offences.

If the air-pressure warning activates, you should have enough air to allow you to stop safely on the hard shoulder. Don't delay stopping, as further loss of air may cause the brakes to lock on. Switch on the hazard warning lights. Use the nearest emergency telephone to call for assistance.

Sitting in a high cab doesn't always give you all-round visibility. Other road users might assume that you can see them and position themselves out of sight close to your vehicle. Making good use of any extra mirrors can help prevent dangerous incidents, especially when parking.