Tom Anderson wrote:
Alternatively, whack in a second portal or a flyover or whatever, and run
Shoreditch - Highbury & Islington - Willesden Junction as another
Crossrail branch!

Or extend the northern extension (!) to Finsbury Park, Stroud Green,
Crouch End, Highgate, Finchley to end by taking over the Mill Hill East
branch of the Northern Line.

It would be interesting to see the reaction from the Crouch Endites
were this to be seriously proposed. They've wanted a tube for ages,
yet this route would mean the loss of the Parkland Walk. When I lived
in Crouch End in the late 90s, there was a proposal to turn the
Parkland Walk into a road and the opposition was immense. A railway
wouldn't be able to generate the same amount of moral outrage, yet the
Parkland Walk would still be lost. I can imagine a lot of heads
exploding with contradictions!

Patrick