Can't see the reasoning for guerrila tactics to catch speeders. If these cameras did the job properly then speeding would have been history years ago. The fact that loads of people still do it proves it's not working.
We have lots of fixed speed cameras in UK, around here they are highly visible and 'Dayglo Yellow', usually in an area clear of vegetation.
The reasoning is simple, it is a visual deterent. Some even don't have cameras inside! Lots of illuminated signs telling us how fast we are going as well.
There is also an experimental road on a town centre ring road near me, with no speed limits, signs or markings of any type, even the road is a confusing multitude of different brick paving colours and patterns. Everyone said it would be a disaster with pedestrians killed and accidents all over the place due to speeding. To my knowledge there have not been any accidents, it is so confusing that people drive really slowly and keep a look out.