Dramatic thread title.
Stupid thing to declare.
Those 20 zones are stupid because they haven't been properly signed, half the time they just get changed overnight with no warning/publicity/large signage, and in areas the councillors live/naice areas protecting naice children, and fuck the regular kids who get nothing like usual.
When a national speed limit turns into a 30 zone, we get a big sign on both sides of the road, and vice versa. When 30 turns to 40 (and back again) the same happens. But these 20 zones just suddenly change and the only way you know is piddly little lamp post "reminder" signs instead of a big sign at the start of the zone making it clear. Of course people are confused/ignore them/try to overtake. It's hard enough getting people to follow speed limits that have been properly signed on the road never mind this nonsense.
And why SHOULD anyone go at 20 past a school at 3am during the holidays??? Time-sensitive speed limits (like on smart motorways) would be much more sane/sensible/safe.