Brian Watson wrote:
"Brimstone" wrote in message
...
Brian Watson wrote:
"Brimstone" wrote in message
...

That's my understanding also, the surface building would need to be
located
elsewhere in the vicinity.

Erm, how about Leicester Square.

(Here we go round again).

Just far enough away to be annoying, from the point of view of
someone who has difficulty walking.

In that we are only talking about an access point, what's the problem
with an escalator down-and-up, or a moving walkway underground,
between Leicester Square and Covent Garden?

There's plenty of space in the Square itself for a new access point.

For those not sure of the geography Leicester Sq station is east of
Leicester Sq in Charing Cross Road and Covent Garden Station is in the
opposite direction from the square itself..

But to answer your substantive question. Probably nothing more than money
and whatever is already underground. More of the former will overcome
problems caused by the latter.