LGV Theory Test 4

The operator of a UK-registered vehicle engaged in the carriage of dangerous goods should make sure that the driver has a valid vocational training certificate. These certificates are valid for five years.

In dense fog, large vehicles are no more visible than any other. If visibility falls below 100 metres (328 feet), use your fog lights to help other drivers see you.

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

The speed limits imposed on vehicles carrying abnormal loads can be frustrating for other drivers, but you mustn't be tempted to exceed them. Remember, the more weight you're carrying, the longer it will take you to stop safely.

Always allow plenty of time for your journey, in case of unforeseen problems such as punctures, breakdowns, road closures or diversions. You'll feel less stressed and less inclined to take risks if you're not under time pressure.

Mandatory speed-limit signs above the hard shoulder and all other lanes show that you're on a smart motorway. In this case, you can use the hard shoulder as a running lane. You must stay within the speed limit shown. Look well ahead for any vehicles that have broken down and are blocking the hard shoulder.

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.

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.

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.

When you have to slow down or stop, you should always avoid harsh, late braking. This is particularly important on icy or slippery roads, where you need to brake gently and in good time to make sure you keep control of your vehicle.

A front tyre bursting will seriously reduce your control of the vehicle. Keep calm and resist the temptation to brake hard or swerve. Hold the steering wheel firmly and try to get the vehicle onto the hard shoulder while allowing it to slow down gradually. Stop as far to the left as possible and switch on your hazard warning lights.

Every year, many people are seriously injured by falling from vehicles. Using suitable steps will lessen the chance of falling. Be aware of the dangers when loading or unloading vehicles.

The type of suspension fitted to a vehicle will influence its resistance to 'roll-over'. Modern tri-axle semi-trailers fitted with single wheels on each side extend the tracking width available, making this the most stable configuration.

Anti-lock braking systems sense when the wheels are about to lock. The sensor control releases the brakes and immediately applies them again. It will do this many times per second. This both prevents skidding and enables the driver to steer - something that's impossible when the steering wheels are skidding.

Make certain that your filler caps are properly closed, so that you don't spill fuel as you drive along the road.

Chilled foods are transported at temperatures above freezing point. Drivers need to be trained in hygiene procedures and how to operate refrigeration units.

It's an offence to leave a vehicle unattended on a public road with the engine running. Take care if you have to open the cab door directly into the road. Look for passing traffic - especially cyclists or motorcyclists - that may not be visible in your mirrors.

It's illegal to use a hand-held mobile phone while you're driving, other than to call 999 or 112 in a genuine emergency. Switch it off before you start driving and use the messaging facility. You can pick up messages when you stop for a rest break. If you must make a call, stop in a safe place before using the phone.

This sign gives you advance warning of a junction where the permanent sign is obscured by roadworks.

Spilt diesel creates a serious risk to other road users, especially motorcyclists. Take care when refuelling and make sure that all filler caps and tank hatches are properly closed and secure.

Some foods need to be transported at controlled temperatures. Drivers will need to be trained in the use of refrigeration units and correct hygiene procedures.

You should change lanes as directed by the sign. Here, the right-hand lane is closed but the
left-hand and centre lanes are available. Merging in turn is recommended when it's safe and traffic is going slowly; for example, at roadworks or a road traffic incident. When vehicles are travelling at speed, this isn't advisable and you should move into the appropriate lane in good time.

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.

This sign is placed on sections of road where overtaking would be dangerous. There'll often be a plate underneath the sign, telling you how far the restriction extends. You mustn't overtake until you pass another sign cancelling the restriction.

At a pelican crossing, the green light means you may go, but you must give way to anyone still crossing. If someone hasn't finished crossing, be patient. People with mobility difficulties can struggle to cross in the time allowed by the lights.

Always plan ahead and take note of gradient warning signs. On downhill gradients, you can help control your vehicle's speed and avoid brake fade by selecting a lower gear in good time.

By using a bypass, rather than joining the stop/start traffic in a town centre, you're less likely to be held up and can travel at a constant speed. Keeping to a constant speed will reduce the amount of pollution produced by your vehicle.

Keeping the height of the load as low as possible will reduce the wind resistance of the vehicle. This will help to save fuel. It's particularly relevant when using a flat-bodied lorry or trailer.

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.

If a build-up of water prevents the tyres from gripping the road, the steering can become unresponsive. If this happens, ease off the accelerator and slow down gradually.

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.

All spare sheets and ropes carried on the vehicle must be tied down securely to prevent them falling onto the road, where they may be a hazard for other vehicles.

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

The smallest lapse in concentration can result in loss of control. Even when your tachograph would allow you to drive for longer, stop somewhere safe and rest if you feel your driving may be affected by your tiredness.

Tailgating is very dangerous because there isn't enough room to stop if an emergency arises. It's also intimidating for the driver that you're following.

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.

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.

The entrances to roundabouts are often worn. This can make the surface slippery, especially when it's wet. You should plan your approach and brake in good time.

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 know which light is going to show next, you can plan your approach. This will help prevent excessive braking or hesitation at the junction.

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.

Standing on or near the edge of the carriageway is very dangerous. Your priority is to alert the emergency services by using an emergency roadside telephone. This connects to an operator, who'll get help out to you as soon as possible. In most cases, this is preferable to using a mobile phone, as it will show the operator your precise location.

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.

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.

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.

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.

It's illegal to drive a vehicle that's emitting excessive exhaust smoke, so you should get the problem fixed as soon as you're aware of it. Excessive exhaust smoke increases pollution and creates a hazard for other road users.

Many learners aren't confident when they first start to drive. Allow them plenty of room and don't react impatiently when they take their time. Remember that new drivers are inexperienced in dealing with traffic situations, so be patient.

When the trailer is loaded, the weight of the load presses the trailer tyres firmly onto the road surface, so improving the tyres' grip. Unladen, there is no load bearing down on the tyres, and under heavy braking the trailer wheels can lock or slide across the road surface, making the trailer more difficult to stop. Severe braking can result in jack-knifing: the trailer doesn't slow as quickly as the tractor unit and this causes it to pivot around the coupling.

If you're carrying a high-value load, you should consider your personal safety. There's always the possibility of an attempted theft. Watch out for and report anything unusual, such as people taking a special interest in you or your vehicle.

When diesel fuel spills onto the road, it makes the road surface extremely slippery. This can cause danger for all types of vehicle, but particularly for those with two wheels, which rely on their tyres' grip to remain upright.

Reflective studs on motorways and dual carriageways are provided to help drivers in bad visibility. Reflective studs are coloured

• red on the left-hand edge of the carriageway
• white to indicate lane markings
• green at slip roads and lay-bys
• amber on the right-hand edge of the carriageway, marking the central reservation.

Driving at a constant speed for long periods, such as on a motorway, can cause drowsiness. Falling asleep while driving accounts for a significant proportion of vehicle incidents. You should plan and take regular rest stops, but if you feel the onset of tiredness between these breaks, stop and rest in a safe place.

You must make sure that you adjust the seat so that you're able to reach all the controls and see in all the mirrors before you start to drive any vehicle. You should also be able to lean out of the window and check your offside blind spots.

Never drive after taking drugs you don't know about. They might affect your judgement and perception - and, therefore, endanger lives.

Drivers of buses and coaches with more than 16 passenger seats require a category D licence. Make sure your licence has the correct entitlement for the vehicle you plan to drive.

Severe braking or selecting a gear too low for your road speed can cause the tractor unit to slow more quickly than the trailer. The trailer can then pivot around the coupling (fifth wheel), causing the vehicle to jack-knife. Jack-knifing is more likely to occur with an unladen vehicle, particularly on a bend or curve.

Take care if you're driving an empty high-sided vehicle when it's windy. Watch for places where the conditions could suddenly change, such as a gap between buildings or when passing under a bridge. Reduce your speed and stay alert for other road users who are also affected by these weather conditions.

Keeping the centre of gravity as low as possible will improve the handling of a car transporter. Top-heavy loads are more unstable and require more care when turning and cornering.

Current legislation requires all operators to set up an 'effective system' to help prevent the carriage of illegal immigrants. This should include vehicle security and checking using a checklist. Failure to do this will incur penalties.

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.

At the scene of an incident, first make sure there's no danger of further collisions or fire before dealing with any casualties. The priority when dealing with an unconscious person is to make sure they can breathe. This may involve clearing their airway if they're having difficulty or there's an obvious obstruction. Don't remove a motorcyclist's helmet unless it's essential, as you could cause them serious injury.

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.

Correctly adjusted air deflectors will save fuel. They should be adjusted to guide the airflow over the highest point at the front of the trailer or load and body.

Never attempt to change direction to the right without checking your right-hand mirror. A motorcyclist might not have seen your signal and could have decided to overtake. This action should be a matter of routine.

If you're carrying a load that consists of loose materials, it must be covered by suitable sheeting. You mustn't risk losing any part of your load. This could cause damage or injury to other road users, and you would be responsible.

Road-friendly suspension reduces the vibration caused by the impact of the wheels on the road surface.

Goods and passenger vehicles with a MAM of more than 7.5 tonnes, those required to be fitted with a speed limiter, and vehicles towing trailers must not use the right-hand lane on a motorway with more than two lanes, unless there are exceptional circumstances.

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.

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.

With a front-tyre blow-out, you won't be able to steer properly. Keep a firm hold of the steering wheel and slow gradually to a stop. Don't brake hard or steer sharply.

A toucan crossing is signal-controlled, but unlike a pelican crossing it doesn't have a flashing amber light in the sequence. Cyclists and pedestrians cross together, and cyclists are allowed to ride their bicycles over the crossing.

You have a legal responsibility to make sure that your vehicle is fully roadworthy. Daily walk-round checks give you the chance to look for any defects with your vehicle.

On a hot day, the fuel in your tank will expand. If this happens when the tank has been filled to the brim, fuel will spill onto the road. This can be very dangerous or even fatal for other road users - especially motorcyclists. Allow for this expansion when filling your tank.

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.

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.

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

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.

You'll generally see this sign at the approach to a pedestrian-only zone.

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.

In windy weather, exposed stretches of road may have lane closures or there may be diversions for some types of vehicle. Consider this when you're planning your journey; delays will add to your driving time.

DVSA or the police can order an immediate prohibition. The vehicle may be immobilised and you won't be able to drive it until the faults have been rectified. Details are notified to the traffic commissioner. Never use a vehicle that you know is faulty.

It's illegal to use a hand-held mobile phone while you're driving. Park in a suitable place before receiving or making a call or text.

If there's heavy rain, the spray-suppression equipment fitted to your vehicle will protect other road users from loss of vision when following or passing your vehicle. Check the wheel arches to make sure the fitments haven't worked loose and no parts have broken off. Well-maintained equipment will force the spray back down onto the road, instead of out to the rear and the sides of the vehicle.

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.

When using ropes, the ends should be spliced or otherwise treated to prevent fraying. The rope should be of at least three-strand construction, with a normal diameter of at least 10 mm.

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 feel the onset of tiredness, you need to take a break. This might be at a motorway service station, but if there isn't one nearby you'll need to leave at the next exit and find a safe place to stop and rest.

There are times when, due to the size of your vehicle, you'll have to take up part of another lane. If you need to do this, make sure that you use effective observation all around. Be aware that other road users might not understand the reasons for your position on the road. You should signal your intentions and take up your position in good time.

There are times when other road users make incorrect or ill-judged decisions. Try to stay calm and don't retaliate or react aggressively, especially as your vehicle is likely to be larger and more intimidating than the other person's. Always put safety first.

You must show consideration to other road users. The reactions of older drivers may be slower and they might need more time to deal with a situation. Be tolerant and don’t lose patience or show your annoyance.

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.

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.

Good forward planning can help you keep other road users out of trouble. Information to help you do this is available if you look for it. Watch for clues: for example, a motorcyclist taking a 'lifesaver' look over their shoulder could be about to change direction.

When turning at a mini-roundabout, it's unlikely that you'll be able to avoid going over the marked area. You should, however, avoid going over the roundabout where possible.