Neighbouring regions are
- England: East and East Anglia
- England North-West
- England South-East
- England: West Midlands
- England: Yorkshire and Humberside
The whole line between Marylebone and Kidderminster is well served by trains and buses (and the Tube within London). The most difficult sections are between Haddenham and Thame Parkway (limited weekday bus connections at Kingswood), and between Banbury and Leamington Spa (weekday bus connections at Kineton). This is a work in progress, and the route has so far been written up between Marylebone and Gerrards Cross.