Swiss Category C Theory (Truck) key terms

The legal state in which a driver cannot safely control a vehicle because of illness, fatigue, alcohol, drugs or medication. Driving in this state is punishable, and the driver must hand over the vehicle or stop.

The general medical and character-related suitability of a person to drive a motor vehicle. It is checked at first licensing and later through medical examinations, especially for professional drivers over 50.

The alcohol concentration in blood, expressed in mass per mille. In Switzerland the absolute limit for motor vehicles is 0.5 per mille; professional drivers and drivers in the probation period are subject to 0.1 per mille.

The classes of driving licence, such as category C for trucks over 3.5 t and category D for buses. Each category has age, training and examination requirements, and category C requires a medical certificate and periodic checks.

A licence category for motor vehicles between 3.5 and 7.5 tonnes. It is a lighter truck category, and holders must still respect the same load-securing, driving-time and technical rules as category C drivers.

The official document listing a vehicle's owner, technical data and permitted weights, dimensions and seats. Drivers of commercial trucks must carry it and show it during roadside checks.

The actual mass of the complete vehicle including driver, passengers, fuel and load at a given moment. It must never exceed the technically permissible maximum weight stated in the vehicle documents.

The difference between the permissible total weight and the unladen weight of the vehicle. It is the load that may legally be carried, and it decreases when the vehicle itself is fitted with heavy equipment.

The mass transmitted to the road by one axle or axle group. Each axle has a maximum permitted load, and overloading one axle can damage the road, reduce steering grip and lead to fines.

Carrying more weight than the permitted total or axle load. It lengthens braking distance, stresses tyres and suspension, and is punishable with fines; the vehicle may be stopped until the excess load is removed.

The measures that prevent cargo from sliding, tipping or falling. It includes form-fit blocking, lashing with straps or chains, and covering loose goods, and it is the driver's legal responsibility before departure.

Securing a load by direct contact with rigid structures such as side walls, headboards or other cargo, so it cannot move. It is the strongest and most reliable method when properly built.

Securing a load by pressure, usually lashing straps that press the goods onto the loading surface. Its effect depends on friction between surfaces, so low-friction loads need more lashings or anti-slip mats.

A tensioned belt used to tie down cargo, marked with its lashing capacity and condition. Damaged straps with cuts, worn edges or broken ratchets must be withdrawn from service immediately.

The way weight is spread over the loading area and axles. Heavy goods should be placed low and near the drive axle, and the centre of gravity should stay as low and central as possible for stable handling.

The point where the vehicle's mass is concentrated. A high or rearward centre of gravity increases the risk of tipping in curves and reduces steering stability, especially on trucks with tall loads.

The distance travelled from the moment the brakes are applied until the vehicle stops. It grows with the square of speed, so doubling speed roughly quadruples braking distance, and it also increases with load.

The distance covered during the driver's perception and reaction time before braking begins. At 80 km/h a one-second reaction time already means about 22 metres of travel before the brakes act.

The total distance needed to stop, equal to reaction distance plus braking distance. It is the key figure for safe following distance and for anticipating hazards such as junctions or pedestrian crossings.

The outward force acting on a vehicle in a curve, increasing with mass, with the square of speed and with curve tightness. It can cause a truck to roll over or slide, so speed must be reduced before entering a bend.

Loss of tyre contact with the road because a film of water lifts the tyre. Steering and braking become ineffective; the driver should ease off the accelerator, keep the steering steady and avoid sudden braking.

The depth of the grooves in a tyre tread. Swiss law requires at least 1.6 mm for cars and 3 mm for heavy vehicles in the main grooves; adequate depth is essential for water drainage and grip.

The air pressure inside a tyre, which must match the manufacturer's values for the actual load. Too low pressure causes overheating, higher fuel consumption and tyre failure; it should be checked when tyres are cold.

The maximum load a tyre may carry at a given speed and pressure, shown as a load index number on the sidewall. Fitting tyres with insufficient capacity for the axle load is dangerous and illegal.

An auxiliary braking system such as an engine brake, exhaust brake or retarder that slows the vehicle without using the service brakes. It prevents brake fade on long descents and should be used continuously on gradients.

Loss of braking performance caused by overheating of brake drums or discs, common on long downhill runs with continuous service braking. The driver should use the retarder, a lower gear and stop to cool the brakes.

A system that uses engine compression to slow the vehicle when the accelerator is released, often with a flap or valve in the exhaust. It saves the service brakes and is especially useful on descents.

The area around a truck that the driver cannot see in the mirrors. Before turning or changing lanes, the driver must check mirrors and use indirect vision aids, because cyclists and pedestrians are easily hidden there.

A collision, often with a cyclist or pedestrian, when a truck turns across their path. It is prevented by early observation, indicating, reducing speed before the turn and checking the blind spot.

The legal priority rules at junctions and crossings, including the right-before-left rule where no signs apply. Truck drivers must give way to vehicles on the right and obey signs and signals exactly.

The system of traffic signs, road markings and light signals regulating traffic. Signs are grouped into warning, regulatory, priority and information signs, and drivers must recognise their shape and colour.

A solid road marking that must not be crossed or straddled. It separates opposing traffic or marks a hazard zone, and crossing it is a traffic offence even when no other vehicle is visible.

The gap a driver keeps to the vehicle ahead so as to stop safely if it brakes suddenly. A common rule is the two-second distance, which must be increased with speed, load and wet or icy roads.

The legal limits on professional driving, such as a maximum of 4.5 hours driving before a 45-minute break, and daily and weekly rest rules. They protect road safety and are checked with the tachograph.

An electronic recording device that logs driving time, rest, work and availability. Drivers must insert their driver card, record activities correctly and produce the data on request during inspections.

A personal smart card used with the digital tachograph to identify the driver and store activity records. It is personal, must not be lent to others and must be replaced when lost or defective.

The uninterrupted rest a driver must take in each 24-hour period, normally at least 11 hours and reducible to 9 hours a limited number of times. It may be taken in the vehicle if it has a suitable bunk.

A regular weekly rest of at least 45 hours, or a reduced rest of at least 24 hours taken away from base in certain conditions. It must be completed within each week and compensated if reduced.

The document that must accompany a dangerous goods consignment, stating the UN number, proper shipping name, class, packing group and quantity. It informs emergency services and must be kept accessible in the cab.

A four-digit number identifying a dangerous substance or article internationally, such as 1202 for diesel fuel. It is shown on the transport document, on orange plates and on packages.

One of the nine ADR classes grouping dangerous goods by hazard, for example class 3 for flammable liquids and class 8 for corrosives. The class determines packaging, labelling and equipment requirements.

The orange rectangular plate on a dangerous goods vehicle showing the hazard identification number and the UN number. It warns emergency responders and must be removed or covered when the vehicle is empty and cleaned.

Immediate help given to injured persons before professional rescue arrives, including securing the scene, alerting emergency services and giving basic care. Truck drivers must carry a first-aid kit and know how to use it.

The call to emergency services, in Switzerland 144 for ambulance and 117 for police. The caller should give location, number and type of casualties, hazards and their own name, then follow instructions.

A reflective vest worn outside the vehicle at an accident or breakdown so the driver is visible to traffic. It should be kept within reach in the cab and put on before leaving the vehicle.

A reflective triangle placed on the road to warn approaching traffic of a stopped vehicle. It is set up at a sufficient distance, further on fast roads, and the hazard lights are switched on first.

A fire in a truck, often starting in the engine bay, brakes or tyres. The driver should stop safely, switch off the engine, evacuate, call the fire service and only attempt to extinguish a small fire with the on-board extinguisher.

A portable extinguisher carried on the vehicle for small fires. Drivers must know its location, check that it is charged, and aim at the base of the flames while keeping an escape route open.

A fuel-saving driving style using early upshifting, steady speed, anticipation and engine braking instead of hard acceleration and late braking. It lowers consumption, emissions and wear on brakes and tyres.

Observing far ahead and planning speed and lane so as to avoid sudden braking and acceleration. It smooths traffic flow, reduces fuel use and gives more time to react to hazards.

Running the engine while the vehicle is stationary. Idling wastes fuel, increases emissions and noise, and should be avoided; the engine is switched off during longer stops unless needed for systems such as refrigeration.

The legal limit on pollutants in vehicle exhaust, such as the Euro classes. Modern standards require exhaust after-treatment, and low-emission zones may restrict entry to vehicles meeting certain classes.

The rear-view and side mirrors, including the front and kerb mirrors on trucks, that give the driver indirect vision. They must be correctly adjusted and clean, since they are the main defence against blind-spot accidents.