TfL's grand vision for turning London's suburban overground services into
the Overground:

http://metro.co.uk/2016/09/21/london...erent-6143328/

I got an idea. Let's just turn the entire network, from Penzance to
Wick, orange.

I note a bunch of arrows at the ends of the various lines, so based on
the text that says they want to take over the various franchises, I
assume we'd have TfL at least as far as Kings Lynn. It would certainly
be handy to pay for my jaunts between Cambridge and Ely with my senior
Oyster.