That's part of the idea behind 20mph limits rather than zones. Limits don't require vertical deflection (which was always built into 20mph zones to be 'self-enforcing'--obviously, while it's still annoying, it also led to cars with much better suspension).
As for the annoying pseudo-mini-roundabouts, they're the consequence of more money being granted to councils under Local Safety Schemes funding where they introduced mini-roundabouts, on the grounds of their (alleged) better crash record (depends on location, and is certainly not likely where a white circle is merely painted into the centre of an ordinary priority junction). This is no longer the case, and as a result you see a lot fewer of them implemented these days.
That's part of the idea behind 20mph limits rather than zones. Limits don't require vertical deflection (which was always built into 20mph zones to be 'self-enforcing'--obviously, while it's still annoying, it also led to cars with much better suspension).
As for the annoying pseudo-mini-roundabouts, they're the consequence of more money being granted to councils under Local Safety Schemes funding where they introduced mini-roundabouts, on the grounds of their (alleged) better crash record (depends on location, and is certainly not likely where a white circle is merely painted into the centre of an ordinary priority junction). This is no longer the case, and as a result you see a lot fewer of them implemented these days.