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.

While moving, hazard warning lights may only be used on a motorway or unrestricted dual carriageway to warn drivers behind of a need to slow down, due to a hazard ahead.

Parked vehicles near junctions can hide smaller road users such as cyclists and motorcyclists. Double-check before emerging with a large vehicle. If in doubt, move forward slowly into a position where you can safely have another look.

Plan your overtaking carefully. The weight of your vehicle, combined with the restrictions imposed by a speed limiter, is likely to make your vehicle lose speed on uphill gradients. You should take this into consideration before attempting to overtake another moving vehicle.

Children can be unpredictable, and when they're in groups they may fool around and push each other into the road. You should drive with extreme caution when you're near them. You need to be ready to stop suddenly.

This shared route is for pedestrians and cyclists only. Be aware that, when it ends, the cyclists will be rejoining the main road.

Horse riders often keep to the outside of the roundabout even if they're turning right. Give them room in case they have to cross lanes of traffic.

You should allow the faster-moving vehicle to overtake safely. If you pull out to overtake at this time, you'll cause the car behind to brake sharply. Don't use the size of your vehicle to intimidate. Be professional and show consideration to other road users.

You need to know the length of your vehicle as well as its weight, height and width. Places where the length of your vehicle may be relevant are

• road tunnels
• level crossings
• ferries
• bridges.

To work out your vehicle's payload, use the following formula: maximum authorised mass (MAM), minus tare weight, equals payload. This is the maximum weight your vehicle can carry.

If you attempt to move a casualty who has a spinal injury, it could cause further damage. Make sure an ambulance has been called for and talk to the casualty to keep them calm.

Drivers are required to take 35 hours of training every five years to maintain their Driver CPC. This can be split into shorter sessions of at least seven hours each. These can be spread over the five years, so effectively one day's training is taken each year. The penalties for non-compliance are the same as those for driving without a licence.

The flashing amber light allows pedestrians already on the crossing to get to the other side before a green light shows to the traffic. Be aware that some pedestrians, such as elderly people and young children, need longer to cross. Let them do this at their own pace.

Although they're advised to wear clothing that's bright or reflective, motorcyclists often wear clothing that's mainly black. This can make them difficult to see, so you must look carefully for them.

Allow the cyclist plenty of room. Give them space and be prepared for them to change direction. To stay safe, they may travel around the roundabout in the left-hand lane.

Driving today requires all of your attention, all of the time. Any distraction, however brief, is dangerous. This is why it's illegal to use a hand-held mobile phone while you're driving.

When making a left turn with a long vehicle, you may have to adopt an unusual position, well over to the centre of the road. Always signal your intentions in good time, and make good use of the mirrors, especially the left-hand one. Be alert for less experienced road users putting themselves in danger by coming up on your nearside.

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

Some lanes are set aside for certain types of vehicle. Signs and road markings show the authorised vehicles in words or pictures. There's usually also a sign showing the times that the lane is in operation. Some lanes might only be in operation for a short time. Check the sign and only use the lane if you're allowed to do so.

If you check the engine oil level when your vehicle is standing on a slope, the reading on the dipstick won't be accurate. Park it on flat ground, so the dipstick shows the true level.

Heavy steering could mean there's a fault with the power steering. It should be investigated as soon as possible. Many large vehicles can become undriveable if the power steering fails completely.

Theft of loads from commercial vehicles is a serious problem. You should take steps to safeguard your load when leaving the vehicle overnight. Simply parking with the rear doors close to another vehicle or a wall can act as an effective deterrent to thieves.

While overtaking, you'll need to judge carefully when to return to the nearside lane. Check your left-hand (nearside) mirror to make sure the rear of your vehicle is well clear. You should allow for the length of both vehicles and take into account the speed difference. Don't cut in too soon on the vehicle you've overtaken, and don't rely on signals from other drivers; they may be signalling to someone else.

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.

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.

Always plan well ahead before overtaking. Take into consideration the size of your vehicle and whether there's a gradient ahead. The load on your vehicle will slow you down on an uphill gradient. It may be better to wait until you're on the level before trying to overtake.

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

If the steering becomes heavy, the power-assisted steering may have failed. It's also possible that your vehicle has a puncture or the load might have shifted. You should stop safely, investigate the cause and call for help if necessary.

In windy weather, try to avoid routes where you would have to drive across suspension bridges and other exposed stretches of road. Plan a route that takes you across lower ground and where you'll be less exposed.

Just before turning, a check in the offside mirror will help you to see any cyclist or motorcyclist passing on your offside. This check may help to prevent a serious incident from developing.

You must take extra care when your vehicle is carrying a load. When cornering, weight will be transferred away from the direction in which you're turning. Also, when you're braking, weight can be transferred in several different directions.

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.

Only change lanes if doing so won't inconvenience another road user. Merging drivers have a responsibility to give way, if necessary, and not force their way onto the main carriageway. Planning ahead will ensure you're prepared to deal with these situations.

This traffic sign means no stopping on the main carriageway at any time, not even to set down passengers. However, you may stop in a lay-by.

Always maintain a safe following distance from the vehicle in front. If another vehicle pulls into the gap, slow down to re-establish a safe following distance. Following too close is dangerous and places you and other road users in unnecessary danger; your view of the road ahead will be seriously reduced, and you won't be able to see or plan effectively.

Red Routes operate in many busy cities and are designed to ensure the route has no obstructions to cause delays during peak periods. Road signs and red road markings identify roads where Red Route waiting and loading restrictions apply.

Before driving into a tunnel, you should take off your sunglasses. If you don't, you'll find that your vision is restricted - even in a tunnel that appears to be well lit.

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.

Local-authority environmental health departments check vehicles' exhaust emissions. They have the power to prosecute the driver and the operator, as do enforcement bodies such as DVSA.

The dangers of drink-driving are well publicised. Anyone convicted of this offence will lose their entitlement to drive any motor vehicle on the road.

A driver's week is defined as a period from 00.00 hours on Monday to 24.00 hours the following Sunday.

A lorry loaded like this will be top-heavy and more likely to overturn in high winds or when cornering. If you're only carrying half a load, you should try to carry it on the lower deck.

Plan your overtaking carefully. The weight of your vehicle, combined with the restrictions imposed by a speed limiter, is likely to make your vehicle lose speed on uphill gradients. You should take this into consideration before attempting to overtake another moving vehicle.

If you don't give your name and address at the time of an incident, report it to the police as soon as you can, or in any case within 24 hours. If any other person is injured and you don't produce your insurance certificate to the police at the time of the incident, or to any other person who has reasonable grounds to request it, you must also

• report the incident to the police as soon as possible, or in any case within 24 hours
• produce your insurance certificate to the police either when reporting the incident or within seven days (five days in Northern Ireland) at any police station.

An illness that could affect you while you're driving, such as a heart condition, may make it unsafe for you to drive. You must tell DVLA if you develop any serious illness or disability that's likely to last more than three months and that could affect your driving. Partial blindness and mental disorders can also prevent you from getting a driving licence for large vehicles.

By driving smoothly, you'll reduce fuel consumption by about 15%, and you'll reduce the amount of wear and tear on your vehicle. You'll also feel more relaxed and have a more pleasant journey.

Make allowances for cyclists. Allow them plenty of room, and be aware that they also have to deal with hazards. They might swerve or change direction suddenly to avoid uneven road surfaces.

If you're travelling on a long journey, plan your route before you leave. This will help you to

• be decisive at intersections and junctions
• plan your rest stops
• know approximately how long the journey will take.

Make sure that the vehicle you're travelling in is well ventilated. A warm, stuffy atmosphere can make you drowsy, which will impair your judgement and perception.

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.

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.

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.

Scan the road as you drive. Try to anticipate hazards by being aware of the places where they're likely to occur; for example, pedestrians and cyclists emerging between parked cars on a busy street. If you're prepared, you'll be able to slow down or stop in good time.

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.

Continuous high speeds on the motorway can cause the tyres to become hot and to shred. If you notice this happening, you must stop on the hard shoulder as soon as it's safe to do so. It's dangerous to drive a defective vehicle.

By planning your journey to avoid busy times, you'll avoid the build-up of traffic that often occurs.

When you have to straddle the lanes at small roundabouts or junctions, always signal in good time. Be alert for inexperienced road users who may, without realising, put themselves into a dangerous position.

Research shows that approximately 40% of SRVIs involve commercial vehicles. The consequences are usually very serious because of the size of the vehicle and the fact that there is no braking before the impact.

The red studs on your left indicate the edge of the hard shoulder, while the white studs are used between the lanes. Using more than one reference point will help you to be certain of your position.

At night, a pedestrian carrying a red light should be at the back of an organised walk. The walkers should keep to the left, but this won't always be the case. Pass them very slowly. Be aware that the pedestrians may have their backs to you and might not know you're approaching.

Learners might not have confidence when they first start to drive. Allow them plenty of room and don’t react adversely to their hesitation. We all learn from experience, but new drivers will have had less practice in dealing with all the situations that might occur.

The type of training required by drivers carrying livestock varies according to the distance, journey duration and species involved. For journeys of less than 65 km (40 miles), no formal qualification is required but you must have practical experience in the care of animals being transported.

Always look into the road you're entering. If pedestrians are already crossing, be considerate and give way to them. Don't wave or signal them to hurry; they have priority here.

Don't drive without a fuel filler cap in place, as fuel could spill onto the road, especially when you're cornering or turning at a roundabout. Diesel fuel will make the road surface extremely slippery. Any spillage should be reported, so that the emergency services can make the road safe.

If you see this sign, be aware that there's a danger of grounding. This can happen where there's a pronounced bump in the road, such as at a level crossing or a hump bridge.

Buffer lanes are often found in places that are frequently subjected to high winds. Examples include high-level bridges, high-level roads, exposed viaducts and exposed stretches of motorway. Listen to the weather forecast, which should tell you of any need to re-plan your route.

If your vehicle is too long to fit into a passing place, you may need to wait opposite one. This will allow a following or approaching driver to pass. When you use this type of road, you need to plan and look well ahead to avoid meeting another road user at an inappropriate place.

Telephone calls can distract you, meaning that you're not in proper control of your vehicle. If you need to use a telephone when driving, find a safe place to stop first. Better still, use a phone answering service and listen to your messages at the end of your journey.

Warning buzzers are linked to many systems on modern vehicles, including the air brakes. A warning light on the dashboard may help you identify the system that's caused the problem. Stop in a safe place until the fault has been identified and put right. Get professional help if necessary.

It can be dangerous for vehicles passing close by if you open the door carelessly. Always look properly to make sure that it's safe - checking the blind spots as well as using the mirrors - before you get out of the cab.

It's not always possible for drivers in the left-hand lane to change lanes to let joining traffic merge. However, you should be ready to adjust your speed to help the joining driver merge safely.

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

Pedestrians and cyclists are shown the green light together. The signals are push-button-operated and there's no flashing amber phase.

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.

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

Switch off your fog lights when fog starts to clear and visibility improves to more than 100 metres (328 feet). Don't leave your fog lights on when the fog has cleared, because they can cause unnecessary glare or distraction for other drivers.

Higher speeds will cause more spray to be thrown up by vehicles' tyres - particularly the tyres of larger vehicles and trailers. Always use dipped headlights in poor visibility caused by rain and spray.

Rain makes the road surface slippery and reduces tyre grip. Doubling your separation distance should allow you the extra time and space you'll need to slow down and stop safely.

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.

Most speed limiters work by taking a speed signal from the tachograph and transmitting it to the engine management system. This reduces the fuel supply to the engine, and allows the speed of the vehicle to be controlled to specific limits. The speed at which a limiter is set must be shown on a plate clearly displayed in the cab. You should be aware of the effect a speed limiter will have on your vehicle, especially when overtaking.

Take extra care when you're driving on roads where trams operate. Look out for road markings and signs that tell you to expect them. Modern trams are very quiet and you might not hear them approaching.

Motorcyclists and cyclists are smaller and usually more difficult to see than other vehicles. Look out for them at junctions; failing to see them can lead to a collision.

On smart motorways, the hard shoulder can be used as a running lane when a speed limit is shown above it. However, a red cross above the hard shoulder means that this lane shouldn't be used, except for emergencies and breakdowns.

When the roads are wet, have consideration for pedestrians walking or standing near the kerb.

When you see this sign, beware of traffic queues ahead. Check your mirrors and reduce your speed. Research shows that you make poor decisions when you're angry, so you're less likely to spot and respond safely to hazards. Be patient when you're delayed and reduce the possibility of being involved in an incident.

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.

Slow down when you see a warning sign for an uneven road. Be especially careful if you're carrying passengers, livestock or fragile items.

A vehicle is most stable when travelling in a straight line under gentle acceleration. Sudden acceleration, steering or braking can cause severe loss of control. For maximum control, keep your driving as smooth as possible.

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.

An engine fire is serious. If the fire breaches the fuel lines, it can easily spread to the fuel tank. If that happens, both the vehicle and its cargo will probably be lost. Therefore, your priority is to shut off the fuel supply.

Tailgating' is the term used when a driver or rider follows the vehicle in front too closely. It's dangerous because it restricts your view of the road ahead and leaves no safety margin if the vehicle in front needs to slow down or stop suddenly. Tailgating is often the underlying cause of rear-end collisions or multiple pile-ups.

The longer top deck needs a wider turning circle than the cab below it. To avoid hitting lampposts, telegraph poles, etc, you must allow for this overhang when turning.

If your vehicle breaks down in a tunnel, it could present a danger to other traffic. First, switch on your hazard warning lights. If there are passengers in your vehicle, take them to the nearest exit point. You should then call for help from an emergency telephone. Don't rely on being found by the police or being seen by a CCTV camera. The longer a vehicle stays in an exposed position, the more danger it poses to other traffic.

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

While you're using a phone, your attention will be divided between the call and the road. This means you're unable to take in all that's happening around your vehicle. You need to be concentrating on your driving all of the time, and especially when dealing with a hazard.