On Tue, 28 Sep 2010, Pat Ricroft wrote:

On 28 Sep, 08:13, wrote:
There's also the problem of deciding where in central London the
southbound line say would change from being 'up' (which is normally
but not always TO London) to 'down' - away from London.

Metrolink (trams) get round this by relating everything to the delta
junction at the centre of the network, near Piccadilly Gardens. They
run inbound services as far as the junction. Once through the junction
they become outbound services.

Quite what will happen if they build the proposed secondary line
through the city centre, bypassing the delta junction, is another
matter.

Roundbound?

tom

--
These spoiled youths forget that when they are shaven they look like
boiled potatoes. -- Tara Singh