Driving technique and vehicle handling
This domain tests whether you can translate physics into habits: mass, height, brake heat and blind spots. The examiner expects you to reason from the vehicle's weight and centre of gravity, not to quote car-driving instincts.
Mass and centre of gravity
A loaded combination of 40 t has a high centre of gravity and a rollover threshold far below a car's. Slow down before the bend and take power through it, never brake hard once turning. Weight transfer under braking loads the front axle and lightens the rear, which is how a tractor unit jack-knifes.
Braking and speed
Braking distance grows with the square of speed: from 80 km/h you need roughly 60-70 m of braking alone before reaction distance is added. Hold at least a three-second gap in good conditions and four to five seconds with a full load, in rain, or on a motorvej. Brake in a straight line; if you must brake and steer, brake first, then steer.
Descents and brake fade
Continuous braking heats drums and discs until the linings fade and the pedal goes long. Select a low gear before the descent begins, let the engine and retarder hold the speed, and use the foot brake only in short, firm applications. In rain or on a slippery surface, ease off the retarder on the drive axle - it can start a skid.
Blind spots and vulnerable road users
Right-hand turns are the classic Danish lorry accident (højresvingsulykke) because cyclists travel along the right side in a blind spot no mirror covers fully. Check the right mirror, the kerb mirror and the cycle path, indicate early, and if in doubt wait. Keep watching the mirrors well past the point where a car driver would stop.
Worked example. You begin a five-kilometre downgrade at 40 t. You brake gently first to lose speed, select a gear that holds about 1,800 rpm without the foot brake, switch on the retarder and descend on that, touching the service brake only for short firm applications to shed a few km/h. The reasoning: the gear and retarder dissipate energy continuously, while a held foot brake converts it into heat until the brakes fade.
Traps that cost marks
- Riding the foot brake down a long hill because it feels safer.
- Delayering a turn with heavy braking mid-corner.
- Judging an overtake by car acceleration; a loaded lorry takes far longer to complete it.