BRITISH RAILWAYS and their actual routings have been something of a mystery since the demise of BR. Look around and whilst there are plenty of timetables and maps of the individual railway companies there is nothing covering the whole country (although to be fair Virgin Rail did have a one off attempt). Even the excellent Transport Direct web site does not offer this information. It has taken an individual, one Barry S. Doe, public transport consultant, to actually produce a free offering. It”s all on his web site.
http://www.barrydoe.plus.com/railmap.pdf
http://www.barrydoe.co.uk