Funny thing, that drive in derbyshire was rife with 40 and 50 limits on what would seem to be perfectly good A-roads at first sight, but after a couple miles driving you got to see that they were actually quite sensible ideas, as it kept you at a good even pace for what could be quite tricky roads in many places, and you really shouldnt be going any much faster. That they had to put a camera in such a feckin' stupid place after i'd been so far through it all was a right annoyance. There had been a couple before, but signposted (this one wasnt!) and easy to see, in obviously difficult (but not "confusing") places.
(another is-it-stupid is-it-genius move was the lines for a Gatso painted where there wasn't one - right on the very boundary of a 40 going into a 30... smart way to make you drop to the new limit without penalising those who are a little slow on the uptake, but also a dumb way of making someone brick themselves and stand on the anchors instead of working off that 10mph gently and safely by easing off the throttle)
Never thought i'd find myself saying that you see.. a sensible 40 or 50 limit on a rural/semirural A road? Surely not...
By contrast there were a lot of more minor roads where there's the usual blanket 60mph limit even though you could safely reach 40 nevermind 60 once in a blue moon... giving eejits free license to try to hit that magic speed (or 50, 70 in some folks minds - whatever, still farrrrrr too quick) and tailgate anyone going slower even if said person is already going just that little bit quicker than they can see to stop.
Bafflingly there were points where it flicked between 60, 30, 60, 40, 60, etc on these roads even though you couldnt travel any slower or quicker between them and a blanket 30 (say... 35? to be bold?) would be far better.
Kind of mixed priorities there!
The whole camera issue makes me glad to live in the west mids where the whole attitude is quite relaxed and cool and they seem to be well-located / signed / out in the open and a last line of enforcement rather than first line of revenue.. all except for the b*st*rd M42 south of J8, of course, which might currently be the country's biggest unadmitted traffic experiment - how effecitvely can we tyranise ordinary people into doing 50 on a 70-80 road by using massive and overbearing numbers of cameras and fear of them? (before the "real" one with the variable speed limit / use-hard-shoulder / etc signs go live)
VS north wales or bloody staffordshire which look to be hellholes for this nonsense.