What should you do?
Check mirrors and blind spot, signal left and move into the left lane in good time.
How to recognise it
A black square with four amber corner lamps and a green arrow pointing diagonally down to the left.
Common confusion
It is the mirror image of the 'Move into the right-hand lane' signal, so check which way the arrow points.
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.
