What should you do?
Plan your lane and route early and check mirrors before slowing or moving to turn off.
How to recognise it
A green rectangular sign with a junction number, N4 in yellow straight ahead, a branch on the left to the R407 for Maynooth and Clane, and 500m at the bottom.
Common confusion
On green signs, national route numbers are in yellow, while regional routes such as R407 are shown in white boxes.
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.
