In November 2017 there were warning signs that Network Rail's UK-wide timetable preparation system was having difficulty keeping to schedule with some changes for the December 2017 timetable still being worked on less than two weeks before issue.
Work on finalising parts of the December 2017 timetable were delayed because NR diverted resources to the "May 2018 Offer" which had to be with the Train Operating Companies by 17th November. For passengers this meant that the normal arrangement of being able to purchase tickets at reduced rates up to 12 weeks before travel was suspended.
Although the May 2018 Working Timetable was completed during November, large parts had to be rewritten due to decisions to incorporate changes caused by electrification and new train fleets in England, as well as the non-arrival of the new electric trains for the Edinburgh-Glasgow route.
The process is now so far behind schedule that the reduced price advance ticket purchase facility is now down to six weeks or less for the duration of the May timetable.
Had Network Rail been devolved so that the 'Scotland Route' was autonomous, these timetable problems would have have been largely confined to England.
For the FNL this means that some journey time reduction resulting from various improvements will not appear until at least the December 2018 timetable.