Absolutely, but that wasn't my point at all. You seem to have ignored that. My point is that there are sections of road that are now 20mph that are safer than some 30 or 40mph sections. It's daft.
If you think some 30mph and 40mph zones need to be reassessed and made slower you can always petition RCT.
The national speed limit on country lanes has always been stupid as most are not safe if you were to drive them at 60mph (and only idiots would)