Okay, so I drive down the A40 (Western Avenue) & A406 (North Circular) roads in London. Let's say the speed limit is 40mph then yes it shows that however, the average speed right hand column will show 50mpoh. Should the speed show 50mph then again yes the correct speed limit is shown however, this time the average speed limit will sow 40mph, starting the alarms for excessive speed.
This is surely a programming error and not something you can as a user rectify??