In the UK I think its actually the cost of fuel that has slowed people down on the motorway.
I've always been relatively well behaved around town in 30 limits because I don't want a dozy pedestrian's death on my conscience. I think motorists these days are perhaps better educated by safety campaigns and more fearful of enforcement.
However I do go fast on deserted B roads where the road ahead is well sighted when the mood takes me. You've got to have some fun at some point, haven't you?
FF
(clean license)