What should you do?
Be aware of traffic joining in the new lane and don't move into it without checking mirrors.
How to recognise it
A blue sign with arrows showing a lane from the left joining the main through lanes, and a 200m plate.
Common confusion
Lane gain means no merge is needed, unlike a merge where traffic must filter in.
Explanation written by the My Driving Test editorial team using the Department of Transport Traffic Signs Manual conventions and the RSA Rules of the Road.
