Our current speed laws I feel are so outdated its incredible, I for one am in favour 20mph outside schools rigourisly enforced by cameras, however in a built up area the speed should be determined by factors which include pedestrian safety etc. On a Motorway increase it to a more realistic 80mph as most people average above 70mph and modern cars have hugely improved braking systems against the vehicles that were around in 67 when it became the permanent limit for derestricted roads (most vehicles at the time struggled to reach above 70).