A Subtle point for Learner Drivers and later Defensive Drivers
Having held licenses on 3 continents (UK,USA, Zambia and the Antipodes) I became aware of the international road signs with the red ring and number in inside on white background.
All students are told that this is the MAXIMUM speed allowed in the area of the road.
MOST students (or have never really learned) that this is NOT the minimun speed.
The car coming up behind please note (who likes to push rather than overtake (and may be rich enough to afford a fine for speeding).