Wilko82, that made me laugh the PCV driver not knowing the speed limit of coaches. I had a few years back a Parks Driver, on the 404, near Bristol Airport overtaking a car doing 30mph in a 50mph zone on double white lines, at about 2am in the morning, as was running very late and was stressed by delays. I know all this as was sitting up front and awake. Parks drivers seem a mixed bunch with some lackadaisical about time keeping and don’t push on at all, even having a smoking break when late, which annoying, to some who get on with it and try keep time.
I find coaches on motorways generally dont speed by more than couple mile an hour except when letting run downhill a bit sometimes, but on A roads etc sometimes they speed a bit, unlike back along time ago when speeds of 80mph plus were quite frequent on motorways, and they definitely pushed on especially if late. I had a M reg Vanhool, with no restrictor, leave Golders Green on time and arrive Leeds 45 mins early, i nodded off with coach doing 80mph and woke up sometime later near Leeds, the drivers said they been doing 85 mph up the M1, was front of coach again.