This discussion on ride quality has me thinking, and is CS relevant I think. Obviously there are line speeds and the 92s have their acceleration / deceleration profile, which I imagine through route learning the drivers understand the braking distance to stop at Crewe, Preston, Carlisle etc.
Obviously the sleeper may go at higher speed than timetabled to make up late running etc. Long dwells at various places as often highlighted here.
But is it written down somewhere, X Section at Rugby, the line speed is 40 (no idea, making it up) but you should take it at 20 (no idea, making it up) for the comfort of the 400 people sleeping behind ? Eg you are permitted to travel at the former, but the latter is preferred.
An interesting point of difference as presumably in most daytime passenger trains, you drive according to the stock limitations and any other safety restrictions, but otherwise get from A to B as quickly and efficiently as possible and permitted.
Apologies for any poor terminology - genuine question.