The trouble with speed limits and cameras to enforce them, is knowing what the limit is. Assuming no problems the speed limit on motorways is 70 and rarely adhered to, even the 40 or 50 through roadworks, imposed to safeguard the workers, is ignored by many (most?). After that who knows for certain what speed limits are in force, particularly in Norfolk where 20, 30, 40, 50 can all be encountered in a very short space, e.g Long Stratton, but there are many others. I am sure they are meant to confuse and become revenue generators. I have no problem adhering to speed limits , but often I am not sure what the limit is.