Safe driving and hazard perception for heavy combinations
Domain focus
This section tests hazard perception and vehicle control for heavy vehicle combinations: stopping distance, blind spots, off-tracking, tail swing, jackknifing, crosswinds and downhill braking.
Core rules
- A laden CE has much longer stopping distance than a car. Reaction distance, braking distance and the trailer's push all increase with mass and speed.
- Blind spots are large, especially on the right and immediately in front. Mirror checks and a final direct check are essential before turning or changing lane.
- In a tight turn the rear wheels cut inside the tractor's path (off-tracking), while the front or rear corner can swing out (tail swing). Give cyclists and pedestrians extra room.
- On a downgrade, select a lower gear and use the endurance brake/retarder. Do not ride the service brake continuously, which can cause fade.
- Crosswinds affect the trailer area; reduce speed and avoid sudden steering. Jackknifing risk rises on slippery surfaces or when the trailer brake is faulty.
Worked example
A 40 t combination descends a 6% grade. The driver selects a low gear, switches on the retarder and uses short service-brake applications only to trim speed. If speed still rises, the driver uses an escape lane or safe stopping area rather than overheating the brakes. The reasoning is that continuous braking converts speed into heat faster than the drums or discs can dissipate it.
Traps
Assuming a car gap is enough; overtaking without checking the trailer's blind spot; braking late into a bend; and using the service brake continuously downhill instead of engine braking and retarder.