A46 - three lane dual carriageways, many section of A14, A74 etc etc….but no hard shoulder.But there on the M25, it's a Motorway not a Dual Carriageway and can have as many lanes a necessary.
Interesting that you mentioned that a Dual Carriageway is named after the separated carriageways because I thought, as I don't think have ever seen more than 2 lanes ( except for the occasional sliproad or separately numbered road running beside it) more than 2 lanes on a Dual Carriageway in the UK.
As the saying goes, every day's a school day!![]()