The blue posts are NOT speed cameras they are for traffic flow observation. Get yourself a GPS based detector (I have the new Snooper S6R Neo). It works very well, and if you were to fit a laser diffuser (not that I would cos that might not be legal!) then you are protected from lasers aswell. Normal laser detectors will just tell you that you are about to get a ticket as it only takes a fraction of a sec for them to get a reading.