Road markings, lane discipline and junctions
This section covers markings, lane use and junction priority. The exam tests whether you can position a large vehicle correctly, obey line types and negotiate junctions without cutting corners or blocking other traffic.
Core rules
A broken white centre line may be crossed when safe; a solid white line should not be crossed except to avoid an obstruction. Double solid lines mean no overtaking. Edge lines mark the carriageway edge, not a parking lane. Stop lines and give-way lines must be respected; stop means a full stop. Keep right except when overtaking, and return to the right lane when safe. Heavy vehicles often have a lower posted limit and may be required to use the rightmost lane. At roundabouts in right-hand traffic, traffic already circulating comes from your left; give way to it and signal your exit. At T-junctions, the give-way line or sign determines priority, not vehicle size.
Worked example
You approach a roundabout in a 12-tonne truck. A car is already circulating from your left. You have a give-way line. The car has priority, so you slow and stop if needed; you do not enter because your vehicle is larger. Signal left after passing the exit before yours.
Traps
Crossing a solid line to make a late turn; using a roundabout’s left lane for a right exit; assuming size gives priority; and stopping beyond the stop line so a pedestrian crossing or junction is blocked.