[jobigoud]

Many places have a minimum speed as well for highways, so that would be illegal. It's probably less enforced than the above-limit infraction though.

[0db532a0]

There is no standard minimum speed limit on motorways in the UK unless indicated by a blue circular sign, which can apply to any road. These are rare. Motorbikes under a certain power limit, disabled vehicles, bicycles and horses are also not allowed on motorways.

There is however the offence of unnecessary obstruction of traffic, which any bellend doing 30mph on a motorway might find it quite possible to be found guilty of.