Drivers were expected to know the limits of their routes and traction and (unofficially), with experience, to what extent they could safely exceed them. Remember, the driver is the first person to collide with something if the loco derails. It would be difficult to know if a driver exceeded the speed limit unless they did it frequently, excessively or in stupid locations. There might be a quiet word with a new driver who appeared to be becoming overconfident before they had much time to gain experience; a more experienced driver who was observed to be doing it a bit too much might be told the shunting-locos can’t go very fast. Officially, it was permitted to go faster than the timetable indicated to make up time, but the wording made it clear that all speed limits should be observed. However, doing your best to get the train back on schedule was seen as a good thing and allowed a multitude of small sins to be overlooked.