To be fair speed cameras are a terrible way to address the problem of speeding. The solution isn't speed limit enforcement, it is road design. If you build a wide straight open road that feels like you're driving on a highway, drivers will naturally tend to drive on it at highway speeds. Slapping a low speed limit on a road like that will make following said speed limit extremely uncomfortable and drivers will naturally tend to go too fast the moment they stop monitoring their speedometer. Hiding a speed camera on a road like that is essentially tricking people into paying an extra tax and speed cameras are often being blatantly used in that way.

The real solution to keeping speeds low is narrowing the street and also if possible making it windy. Use the space to add trees and protected bike lanes. Suddenly drivers will feel comfortable driving a slower speed without the need for a speeding camera. As a bonus it improves the safety for cyclists and pedestrians far more than a stupid speed camera ever would, and it makes the road far more enjoyable to use for everyone, including the car drivers.