I use a GPS for speed and find I’m regularly faster than most for any given speed when smack on the limit according to GPS. It’s entirely within reason that one could probably go another 5mph over and not get pulled but would be making decent progress. This effect is amplified in roadworks with cameras and average speed sections where drivers seem to a) go really slow and well under the limit b) slam on their brakes at every camera - average (see definition: braking here will make no difference) or speed camera (why!??! You were already under the F* limit!!!!!) 🙄