Speed cameras are about 2km from the warning signs. They are either little poles like a sawn of lamp post or squat grey boxes. They issue speeding tickets that are unenforceable over her, or at least they never bother.
Police speed traps are set up on the approaches to the channel ferries. The start point is by a small side road with a cop on a bike. The end point is by a cash machine normally by the beginning of that small side road. At one of these I saw six cash machines in constant use by GB cars in a rush for the ferry. These fines are inescapable .
High vis jacket inside the cabin is a good idea as it stops the arsey cops giving you an easy fine. Headlights are pointless with modern sealed units, breathalyser is no fine issue.
Driving standards are way lower than here in terms of observation, concentration and anticipation but lane discipline better.
Cops hate speed trap detectors so hide them real quick if you use one