Your passengers should be your first consideration. It's your responsibility to deliver them to their destination safely and on time. You should also treat passengers courteously at all times.

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.

As soon as you detect a fault on your vehicle, you must take action. Where faulty brakes are concerned, you need to seek help immediately. Always report minor faults as soon as you detect them. Minor faults can become major ones if they aren't repaired quickly.

On a quiet country road, always be aware that there may be a hazard just around the next bend, such as a slow-moving vehicle or pedestrians. There might not be a pavement and people may be walking on your side of the road.

At the scene of an incident, if there are any casualties who are in contact with live electricity, don't touch them with your hands - even if you're wearing gloves. You should use a dry, non-conducting item, such as a wooden sweeping brush or plastic spade. You mustn't give first aid until you're sure the electrical contact has been broken, otherwise you'll be putting yourself in danger.

You won't have failed in your statutory duties if the boarding device breaks down and there's no other means of assisting the passenger.

Look out for signs giving you advance warning of height restrictions. As a professional driver, you should always know the height of your vehicle or load. If you aren't sure of the safe height, stop and check.

If you're waiting to emerge from a side road, remember to look for motorcycles. Their small size makes them easy to overlook. Be especially careful if parked vehicles are restricting your view. If you can't see, don't go.

Traffic commissioners are responsible for administering the regulations governing a PCV operator's licence. They can take disciplinary action against an operator who falls foul of the legal requirements.

Large or long vehicles have many blind spots. It's vital to check all these areas before starting to reverse and then make sure you keep checking all around while completing the manoeuvre.

Many buses and coaches have a large panel of warning lights on the dashboard. A system check built into the ignition system will allow you to check that all the warning-light bulbs are working before you start your journey. If a warning light stays on, there's a fault. Have it checked before continuing. Remember, your passengers' lives are in your hands.

Continuous use of the brakes can result in them overheating and losing their effectiveness. This is known as 'brake fade' and it's most likely on long downhill gradients.

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

When passing other road users - especially motorcyclists and cyclists - in wet weather, the spray from your vehicle could affect their control. Leave plenty of room as you pass, and look in your left-hand mirror to check that they're still in control.

Individual axle weights are shown on the vehicle plate. This can be found in a prominent place on both the vehicle and trailer.

The term 'crawler lane' doesn't mean the lane is only for extremely slow vehicles. It's advising you of an extra lane on the left. Crawler lanes are usually built on sections of road where the length of the gradient is such that some large vehicles will be slowed to the point where they become a hazard for other road users.

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.

A long lorry with a heavy load will need more time to pass you than a car. It won't be able to accelerate enough to pass you quickly, especially on an uphill stretch of road. Be considerate to the lorry driver - ease off the accelerator and allow the lorry to pass.

Continuous use of the brakes will cause them to overheat, and in extreme cases they'll become ineffective. When you're going downhill, the momentum of your vehicle will cause you to gather speed very quickly. Use the endurance brake (retarder) and stay in a low gear to reduce the need to use the brakes.

To prevent your wheels from locking, you'll need to brake very gently on ice. Give yourself as much room and time as possible to stop. If your front wheels lock, you can't steer, and that will mean you can't avoid any obstacle in your path.

Don't try to enforce the speed limit by blocking another vehicle's progress. This is likely to cause the other driver to become more frustrated. Slow down or move over when it's safe and allow the other vehicle to pass.

Most diesel engines use a high-pressure fuel-injector system that will deliver pressurised fuel directly into the combustion chamber of the engine. This system is known as a direct-injection engine.

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.

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.

As well as a height restriction, the tunnel may have a restriction on the available width of headroom for high vehicles. The advance warning gives you the opportunity to find another route if your vehicle is too high or wide to drive through the tunnel.