For me, this is a misrepresentatiin of the real facts because the simple truth is that if the person at the front of and vehicle group is doing 20 mph, then it stands to reason that everyone behind them will be doing the same or less; therefor, it's a misrepresentatiin that is built on impractical evidence...
On the flip, the intention of the Sennedd to get people back walking or on their bikes might just work; because experiences so far prove that it is now nigh on impossible for your average motorist to pass a cycle without breaking the spped limit on a 20 mph road...!
I will say that I am very much against this blanket speed limit that takes very little into real account but I a supporter of variable speed limits, where they are genuinely needed, e.g.
outside schools during school hours and at other busy areas where a mix of vehicles and pedestrians are more crowded...
Had it been better devised rather than this 'blanket' covering, I believe it might have been better received; but it will remain a bone of contention for some time to come...