Surely the most lowly of all Northern Ireland's collection of diminutive motorways is the poor little A8(M) - and that's saying something. When the M2 was started it headed this way, but a very last-minute decision was taken to re-route the M2 via Antrim. This bit was already built and was left as a tail-end of motorway even though none of the roads concerned had been opened.
The A8(M) isn't unusual in connecting to no other motorways - roads on the mainland like the M2, A3(M) and various parts of the A1(M) don't connect to another road with motorway restrictions. It is, however, unique in having no other junctions in between.
It has arguably the most pointless imposition of motorway restrictions of any road in the UK, because it connects nothing but all-purpose roads and is only a mile long anyway. All the more reason to celebrate something so odd and wilfully arbitrary - three cheers for the A8(M)!