Merging Rules

Where two lanes merge into one (i.e. lane lines end) the vehicle in front has the right of way.

If there are dual lanes, and the lane you are in ends, give way to the vehicles in the lane you are moving into.


  • Always use your indicator to signal your intentions to other drivers when merging;
  • Keep a safe distance between your vehicle and the vehicle in front of you and take turns to merge if there are long lines of merging traffic;
  • You need to match the legal speed of the road you’re merging into.
Offence Penalty Demerits
Failing to give way when merging $100 2
Failing to give way when changing lanes $100 3

Freeway Merging Rules

In April 2014, marked dotted lines (merge lines) were painted on three Kwinana Freeway on-ramps in a trial designed to help drivers merge more efficiently and to improve traffic flow.

The new merge lines were used to prompt motorists to get up to speed and merge into freeway traffic in the same way they would if they were changing lanes.

The trial saw positive results with fewer merge incidents and better traffic flow on the freeway. Based on the trial's success, Main Roads will now introduce new merge lines at all freeway and highway on-ramps across the Perth metropolitan network.
The new merge lines will replace the current practice of merging where the lane lines end. The new merge lines mean similar rules to 'normal' lane changes now apply.

When merging with traffic on the freeway, motorists should:

  • Get up to speed;
  • Indicate their intention to join freeway traffic; and
  • Move into the gap at the earliest and safest opportunity. Just like changing lanes.
The new merging lanes on freeways were be completed in April of 2016 this year, while highway merge lines are expected to be finished by May 2017.

For more information, visit Main Roads WA.

The information available on our website provides a simple interpretation of the law and is not intended to constitute legal advice. Full details of traffic offences and penalties are contained in the Road Traffic Code 2000.