Drive Articulated Vehicle in Normal and Adverse Road/Traffic Conditions
What this domain tests
Driving a tractor-trailer in normal traffic and in rain, fog, night, wind, steep grades and roadworks, using the vehicle's geometry and braking systems correctly.
Core rules
- The combination pivots at the fifth wheel and the trailer wheels cut inside the tractor's path (off-tracking). Allow extra room on every turn and watch the trailer tyres in the mirror.
- Turn wide but not lazy: approach from the correct lane, swing only enough to clear the curb, and keep tail swing clear of poles, pedestrians and parked cars.
- Reverse only with a spotter you can see, or get out and look. Use slow, small steering inputs and correct before the trailer angle grows.
- On a downgrade, select a low gear before the descent, use the engine brake, and use graduated snub braking. Do not ride the service brakes.
- In rain or fog, reduce speed, increase the gap, use low-beam lights, and avoid cruise control and aggressive engine braking on slippery surfaces.
Worked example
You must turn left at a tight intersection. Reasoning: the trailer's rear axles will track inside the tractor's line, so turning early puts the trailer over the curb; turning from the wrong lane puts the tractor into oncoming traffic. Solution: take the right-hand lane if allowed, move forward until the tractor clears the corner, then steer left, checking the left mirror for the trailer tyres and the right mirror for tail swing. Speed at the apex should be walking pace.
Traps
- Cutting the corner and mounting the curb with the trailer.
- Braking hard while turning, which can jackknife a lightly loaded rig.
- Using the engine brake on a wet or icy bridge.
- Reversing without a spotter because 'it's only a few metres'.
- Assuming a car in the mirror has seen you.