On the face of it, the consensus of opinion seems to be that there’s more to driving safely than abiding by speed limits, and an advanced driver should be able to judge for themselves what is a safe speed. Furthermore, some argue that our attention is better occupied dealing with potential hazards than looking at our speedometers. Several obvious points are being missed here:
Firstly, driving within the speed limit does not automatically make you a safe driver, but driving in excess of them DOES make you a dangerous one! Why? Because speed limits are there for a purpose, and that purpose is primarily to improve safety. If you exceed a speed limit, there’s a good chance you’re driving faster than has been deemed safe for that particular stretch of road.
Secondly, a competent driver should be able to judge his or her speed without constant reference to the speedometer.
Thirdly, driving at a legal speed or driving safely are not two opposing options from which to choose from. We must do both
S/He misses the point. Speed limits are set for three prime reasons :
1) to firmly guide inexperienced and under-skilled drivers away from exceeding safe limits by wild margins
2) to provide a ready means of prosecution of those who use speed dangerously
3) to provide a standard warning of expected hazard density
So when the speed limits are set wrong it badly alters these points and learned behaviours.
When the 85th%ile was used, it all 'made sense' and most drivers were not outwith the Law, but now with artificially set low limits, when they use the 'average mean', we now regularly see a deliberately and artificially set lower than necessary speed limit, that makes the majority illegal.
That is seriously dangerous for all road safety.
Slower is not necessarily safer.