The most important development in post-war Britain was the construction of the road and motorway infrastructure. As well as increasing geographic and social mobility, it led to the death of an affordable public transport system, the monopolisation of the retail industry by the big 5 supermarkets, the brutalisation of out-of-town architecture (see Kunstler's Geography of Nowhere for an American perspective on this ), and the rise of commuting and the displaced individual.
Central to making the roads manageable was Frank Blackmore, who invented the mini-roundabout.
Blackmore died last week, but part of his legacy is pictured above - The Magic Roundabout, highpoint of any trip to Swindon. Blackmore was a true eccentric - his family snaps were of roundabouts and junctions from around the country and in his home he had the rubbish bin placed in the middle of the kitchen to ease family traffic around the cooker and sink.