"mark townend" wrote in message
...
On Mar 6, 6:14 pm, D DB 90001 wrote:

I agree that it would be costly, but not as costly as a new circle line. .
. . .

In addition, building a new line would require a lot of new stations,

Agreed all this would be very expensive and disruptive. Removal of all
the flat junctions [......snip....]

Anyway purely for my own interest I've drawn up some of these ideas,
and any constructive comments from the group would be most welcome!

See my proposals here -

http://www.townend.me/files/circlenorth.pdf

With a spelling error, and a punctuation error, in the very first sentence
of that document, I cannot see anyone with clout bothering to read any
further, no matter how laudable the prposals seem to be.