Heavy Vehicle Road Rules and Safe Driving
The core idea
Heavy vehicles obey the same road rules as cars, but the physics of mass and length change what "safe" looks like. A laden rigid truck or articulated combination can weigh 10–40+ times a car, so stopping distance, following distance and speed management dominate the exam.
Concepts you must know
- Stopping distance = reaction distance + braking distance. Braking distance rises with the square of speed, so doubling speed roughly quadruples braking distance, before you add the mass penalty.
- Following distance: the general rule for heavy vehicles is a minimum 4 seconds behind the vehicle ahead in good conditions, extended in rain, at night, or when loaded. Questions often offer 2 or 3 seconds as a trap.
- Swept path and off-tracking: long vehicles cut corners and the rear wheels track inside the front wheels. When turning, check mirrors and allow for the trailer swinging wide.
- Blind spots: heavy vehicles have large blind areas directly in front, beside the cab and behind the trailer. Never assume a truck driver has seen you.
- Rail crossings, low bridges and roundabouts: heavy vehicles need more room and time; approach slowly and commit only when the path is clear.
Traps in questions
Watch for "best" vs "legal" wording - the exam usually wants the safest answer, not the minimum legal one. Distractor options often describe car-sized behaviour (short following gaps, late braking, overtaking on crests).
Rule of thumb
Pick a fixed object the vehicle ahead passes, count seconds until you pass it. Under 4 seconds in dry conditions = too close. In rain, aim for 6+.