Safe Driving and Defensive Driving Techniques
Defensive driving questions check whether you drive for the mistakes of others and for the physics of a loaded vehicle. A 30 t combination cannot be driven like a car: mass multiplies braking distance, and height multiplies rollover risk.
Space and stopping distance
- Total stopping distance = thinking distance + braking distance. Braking distance rises with the square of speed, so 80 km/h needs about four times the distance of 40 km/h.
- Use the three-second rule in dry conditions; double it in rain, on the first rain after dry weeks (oil and dust on the surface), at night, or when fully loaded.
- Keep a longer gap ahead of a heavy vehicle because you cannot see past it and it cannot stop behind you quickly.
Habits that score
- Scan 12–15 seconds ahead, not just the bumper in front; look for brake lights three vehicles ahead.
- Mirror–signal–manoeuvre, and check the blind spots on both sides before every lane change.
- Cover the brake at junctions; expect pedestrians, motorcycles filtering on the right, and vehicles emerging without looking.
- Select a low gear before a descent, not during it, and let engine braking and the retarder share the work.
- Never swerve a loaded truck to avoid a small hazard; brake in a straight line and keep the vehicle stable.
Worked example
You are on a wet downhill at 70 km/h with 25 t on board. A car pulls into your 40 m gap and brakes. Reasoning: three seconds at 70 km/h is about 58 m, and wet conditions double the requirement, so the gap was already too small. Do not swerve - a loaded truck will roll. Release the accelerator, apply the brakes progressively, downshift as speed falls, and accept the longer stop.
Traps that cost marks
Closing up to "help" a car overtake; using the horn instead of reducing speed; assuming a car driver has seen your mirrors or indicators.