Merging causes confusion because two roads can look similar from the driver’s seat while having different give-way rules. Driving instructors should teach students to read the road markings first, not guess from the shape of the road.
Situation one: two lines of traffic becoming one
Where two lines of traffic merge into a single line without a marked lane ending between them, the zip-merge principle applies. A driver must give way to a vehicle to the left or right if any part of that vehicle is ahead of their vehicle.
In everyday language, this is often described as the vehicle ahead going first. That shortcut helps beginners, but it should be linked to the actual position of the vehicles, not interpreted as a right to force a merge.
Situation two: a marked lane ends
Where marked lanes exist and one lane ends, the driver whose lane is ending must give way to traffic in the lane they are entering. This is the familiar lane-change or lane-ending situation. The zip-merge rule does not override the lane markings.
Teach learners to identify the dividing lane line, the lane-ending warning signs and the point where their lane is no longer available. An indicator communicates intention; it does not transfer the give-way obligation to another driver.
Make the lesson an identification exercise
First, show two situations in a simple sketch: one with two lines of vehicles and no dividing lane marking at the merge, and another where a clearly marked lane ends. Ask the student to decide which driver must give way and explain why.
Next, practise low-traffic examples. Have the student scan forward, check mirrors, assess the space, signal where required, check the blind spot and adjust speed smoothly. Avoid deliberately placing the learner beside another car at the narrowing point.
Common instructor observations
A student may watch only the vehicle beside them and forget the vehicle ahead. Another may indicate and immediately steer, assuming the other driver will make room. Some learners brake hard at the end of the lane because they did not anticipate the merge early enough.
Each error suggests a different training need: road-reading, gap judgement, appropriate signalling or forward planning. Rather than saying only “you merged incorrectly”, name the missing decision.
The coaching takeaway
Teach the student to ask three questions: Are there marked lanes? Which lane or line continues? Who must give way at this location? Then practise the observation and speed-control skills needed to act on the answer.
The safest merge is predictable and cooperative, but courtesy never replaces the applicable road rule.
For instructors and training candidates: Explore DAA training and services. DAA provides training and preparation services; it is not the South Australian licensing regulator.
Official sources checked
- South Australian Government official guidance
- South Australian Government official guidance
- South Australian Australian Road Rules (current authorised version)
Related starting material: Happy Driving School original guide / insights. This DAA article is newly written for instructor education, not a republication.
Educational material, reviewed against public guidance on 16 October 2026. Not legal advice or an official competency assessment. Check current legislation, DIT guidance and approved assessment instruments before publication or use in formal assessment.