Our congested roads and driving safely will often dictate speeds will more often than not mean we have to travel at less than speed limits allow.
But when road/traffic conditions allow we all despair at what are all too often unduly restrictive speed limits inherited from bygone years that reflected cars limitations then.
Even the Highway Code contains advice a good many drivers on the road appear to be unaware of, including when overtaking on the left is allowed and advised, in particular Sections 168-169:
https://www.gov.uk/using-the-road-159-to-203/overtaking-162-to-169
It is also a shame that the principle of slower cars pulling over for faster cars used on some of Scotlands rural roads is not extended across our Isles:
http://web.undiscoveredscotland.com/usfeatures/singletrack/
Look at the pic of the police notice and the general advice that would make our progress far more rewarding if more drivers were considerate of others behind them as its says in that link:
"Finally, don't let your concentration on what's coming the other way stop you keeping a close watch on your mirror. If someone comes up behind you, they're obviously travelling the road faster than you are. You should use a passing place to pull over and let them through. This is more than simple courtesy: the road signs above right emphasise the point. And anyway, it is much more comfortable travelling these roads without that same white van sitting on your rear bumper."
But all too sadly there do too many drivers of all ages who seem to lack common since and quite how you deal with them God only knows..........