I think 18 is reference to the extra player, incase of injuries or last minute pullouts.

This has to be a squad member in my eyes as who else would know this information.

I can't see them doing the home return journey without at the very least one toilet break.
If the coach had only one driver on board I think the maximum amount of time he can drive without a break is four & half hours

Skeptical says I. The word defeat appears once to often for my liking.

Nine hours driving which can be extended to ten twice in a fixed week , so with Stebonheath park a good four hours away I would be surprised if the bus drove continuously all the way there and home ,unless the bus has toilet facilities onboard?

One driver could be cutting it fine with his hours if he hit major traffic issues , (which by the sounds of it is possible given the posters comments that the team arrived late ) so i would have thought it would be a journey for two drivers just to be safe.

The more I read the original post the more I feel this is a disgruntled team member or past player with links to the current squad as who else would know this information as i cant see many fans making the trip.

The tachograph disc could be an interesting read.