"Steve Fitzgerald" ] wrote in message
...

Regarding an earlier comment about why the Picc uses east-west when it
'patently isn't'. Well it's safety; the Picc has been defined as an
east - west railway and references internally stick to that. After all,
it is possible to approach Cockfosters heading virtually west on the
eastbound but it would be silly to keep changing the references as that
would just cause confusion. Once we know which is the eastbound or
westbound road it doesn't matter which actual direction it goes; we could
call them direction Fred and direction John for all it matters as long as
everyone knows what we're talking about.

In my experience this is very much the way that American highways tend to
work; they are nominally east-west or north-south but don't necessarily
follow this direction for their entire length, and compass points are always
used on signage to indicate which direction you are going in. Because it's
common in America for one stretch of road to form part of more than one
highway, you'll sometimes see a road which carries more than one number and
more than one direction (I'm not sure if I'm explaining it very well;
perhaps an American could put it better). In any case the emphasis on
compass points can take some getting used to for a British visitor driving
in America for the first time, and it can be helpful to compare it to the
use of north/south/east/westbound on the underground.

Knowing this, I'd often wondered whether this convention on the underground
originated as an example of American influence on the Yerkes tubes, but have
never found out for certain

Martin

Martin