Drove over the Rhygos mountain to Tesco's Aberdare this morning and saw two stretches of road with new 20 mph speed limit signs. The fact that signs are being out up (in certain areas at least) suggests that we aren't just talking about a "default" 20 mph figure (whatever that means) here, once you reach a stage where new signs are being put up to coincide with the law change, you're talking compulsion.