Thought there might be some interest in the following extract from the Greens manifesto :-
Reduce speed limits (e.g. to 20mph in built-up areas, including villages). Introduce a maximum speed limit of 55mph on motorways and trunk roads, and 40mph on rural roads, to make them safer for all road users. Prioritise public transport, then if necessary work towards the introduction of road pricing schemes like the London congestion charge.
I admit I was surprised by the 55mph proposal.
Andy C