After a lesson recently I realised that some learners struggle with working out whether or not they are driving on a dual carriageway so I thought I’d write some hints and tips. It is important you understand whether or not the road you are driving on is a dual carriageway as if the national speed limit applies you could end up 10 mph over the speed limit or alternatively driving too slowly. You also need to be able to tell the difference between a dual carriageway and motorway as you are not permitted on a motorway in certain conditions if you hold a provisional licence although your supervising driver should know this.

Dual carriageways and motorways have a central reservation, single carriageways only have road markings. This is often a crash barrier but not always, sometimes it’s just a small kerb or it could be a grass verge, sometimes trees can prevent you seeing the other side. The point is that if you would need to step over something if you were crossing from one side to the other it is not a single carriageway.
Dual carriageways have dark green signage, motorways have blue signage.
Dual carriageways and motorways will have different coloured cat’s eyes – red on the left, orange near the central reservation, green for slip roads, laybys etc., and white for lane dividers.
It doesn’t matter how many lanes there are – you can get single lane dual carriageways and multi-lane single carriageways.
Look out for the signs on approach such as "Dual carriageway ahead" and ‘keep left’ (on the central reservation).
As you reach the end of the dual carriageway you will see a warning sign if it is becoming a single carriageway.