Road Rules and Safe Driving for Heavy Vehicles
Core rules that differ for heavy vehicles
Heavy vehicles follow the same road rules as cars but with extra obligations. Keep left unless overtaking on multi-lane roads. Obey the posted speed limit; heavy vehicles may have a lower limit on some roads, and speed limiters apply to certain heavy combinations. Maintain a safe following distance - the guideline is at least a three-second gap in good conditions, more in rain or at night, and far more when loaded. Heavy vehicles must not travel in a lane marked for buses or special vehicles unless permitted. Give way rules, roundabout lane discipline, and turning across traffic all demand extra planning because of vehicle length and blind spots.
Traps in questions
The classic trap is the following-distance rule: answers offering a fixed metre gap regardless of speed are wrong; the gap is time-based. Another is overtaking on the left - generally not permitted unless lanes are marked for it or traffic is queued. Questions on railway crossings expect you to stop, look and listen, and never enter unless the exit is clear - heavy vehicles cannot stop quickly. Watch for 'must' versus 'should': only the road rules create legal duties. Also be alert to school zones, roadworks speed reductions, and the rule that you must not reverse further than necessary.
Rule of thumb
Three seconds minimum in ideal conditions; double it in wet weather or when fully loaded. If in doubt, add a second.
Worked example
A 40-tonne B-double travels at 90 km/h. Three seconds at 90 km/h is about 75 metres. In rain, double to six seconds - about 150 metres. A question offering '50 metres at all speeds' is wrong on both counts.