Passenger-car learners are often taught to stay within their lane, but large turning trucks sometimes need more road space than a car driver expects. An instructor should help the learner recognise the risk before the truck begins its turn, especially at narrow intersections and roundabouts.
A truck’s path is wider than the view from the cab suggests
Long vehicles may swing out before a corner and their rear wheels follow a different path from the front wheels. The inside of a turn can therefore be dangerous for a nearby car or bicycle. This is a geometry and observation problem as much as a patience problem.
South Australia’s Driver’s Handbook explains that longer vehicles displaying Do Not Overtake Turning Vehicle signs may need more than one lane for a safe turn. The legal concessions are conditional; the presence of the sign is not an unconditional right for a truck to move without regard for others. Equally, a driver must not overtake to the side towards which a vehicle displaying a Do Not Overtake Turning Vehicle sign is signalling and in the process of turning.
Coach the learner to predict the turning envelope
Approaching a truck at an intersection, have the learner identify the indicator, rear signage, trailer position, available corner space and nearby vulnerable road users. Ask: “If the front of the truck turns left, where could its rear wheels travel?” The aim is to recognise the area the truck will need, not to calculate its exact wheel track.
Teach the learner to stay back when the truck’s path is uncertain. A car alongside the trailer may disappear from the truck driver’s view. The learner should not rely on the truck driver making eye contact or stopping midway through a turn.
Respect the difference between awareness and heavy-vehicle instruction
This article is designed for car-driving instructors teaching safe interaction with heavy vehicles. It does not claim that a car instructor is qualified to deliver heavy-vehicle licensing or specialist manoeuvre assessment. DAA’s heavy-vehicle training pathway is a separate professional subject.
A practical observation exercise
Use a safe stationary viewpoint, a parking-lot discussion or suitable public-road observation where the learner can see turning trucks without entering their operating space. Ask the learner to narrate what the truck needs to do and identify a position where the car can wait without obstructing it. During an actual drive, avoid deliberately placing the learner beside a turning truck for demonstration purposes.
Debrief the decisions made early: Was the truck indicator noticed? Did the learner recognise the warning sign? Was enough space left for the rear of the vehicle to swing? Good instruction rewards anticipation instead of a last-moment evasive movement.
Official references and further learning
- South Australian Driver’s Handbook: Sharing the road with heavy vehicles
- South Australian Driver’s Handbook: Overtaking
- South Australian Driver’s Handbook: Signals
Explore DAA heavy vehicle driving instructor training.
Road-law information checked against the linked South Australian Government sources on 16 October 2026. Educational commentary only; always check the currently authorised rules and the requirements applicable to a specific training or assessment program.