It is because of idiots like you that people are killed in car crashes, the speed limit is there for a good reason
Sorry Freddo, but that is the majority of time is not true. Speed does not kill, bad driving does. I drive to the conditions of commonsense.
Many speed cameras are put in to maximise revenue and never so much as saved a life or prevented an accident. In fact in the UK there has been a few issues with the amounts of signs/cameras which it has been argued caused more accidents as paranoid road users spend more time looking at the side of the road for speed signs/cameras, than they do looking at the road = more accidents.
So, innapropriate speed kills, put up cameras outside schools, where pedestrians are vunerable etc - put them up, on an open road for no reason at all and IT'S ALL ABOUT THE MONEY - they bullshit you with the safety, we are beyond this now - there's enough evidence around to show where many cameras are put in are a nonsense and have no benefit in safety .
So, I have a Mivue dash cam, which has a built in radar database (not a detector), but you can add locations if not in the database, to remind you where any cameras are, should you forget. I do find it useful, as do approach speed cameras as it does make you aware of you local speeds and I know what speed I should do on the road, rather than panicking when see a speed camera and not sure what speed I should be doing.
Something like this, few different options available.
https://www.amazon.co.uk/Mio-TouchScree ... ords=mivue
I would also like to state speed perception is very different in what vehicle you are in & in a modern car with decent performance, it is quite easy to creep over the local limits without noticing it - which is why the councils put up the speed cameras on wide empty roads, where the only thing you are likely to hit is a hedgehog if crossing the road!