If you are planning to drive around here, they are currently installing hundreds of yellow short pole cameras at traffic lights and also speed cameras on any long straight road. I just saw another 5 when in Exeter Today. Very soon they will have the unmarked camera vans that other forces are using to catch speeders. Of course, you will be alright if you have insurance, belts on and not using a phone or speeding or jumping red lights but its becoming an eyesight test lately.
Most of the speed camera have no advance warning although some in Exmouth do but they tend to be fitted on downhill 30 mph roads to make it trickier.
Cornwall always did have a lot of cameras so Devon is catching up now