I have ridden on some motorways, mainly by accident,
In Germany, when staying at a campsite, seemed to be a nice road surface, but was pulled up by a policeman with a stick on blue light Kojak style. Pretended I knew no German, so he tore me off a strip in English and sent me off at the next exit.
In Norway, through one of the tunnels that was restricted to cars only, so a sort of motorway!
In France on the way back to Calais late at night on the way back from Dunkerque to watch the tour prologue, and got misdirected by a French Police Officer onto the motorway No-one took any notice,
and also with Colin Davies on the way back from Grenoble, but turned back as it was very busy.
In UK, A102M to get to eastway when in a hurry, but only a short section, and the Limehouse Link tunnel, which is also a no-no for bikes, but was tucked in behind a cement lorry, so no-one saw me!!!!
Anyone remember Pete Adams - on the return from Brighton, he steamed straight on to the M23 at Pease Pottage