Richard J. wrote:
Michael Hoffman wrote:

In the Tube signs standards document [1], LU mentions switchable
signs (section 1.11). These have white text on a dark blue
illuminated patch. Can anyone tell me how and why these are used?
And where? There are some photos showing them in Waterloo, but it's
a big station.
[1]

http://www.tfl.gov.uk/tfl/downloads/...al_Dec2003.pdf

[Hint: don't put footnotes after your sig, as they get removed by some
news software when replying]

[Hint: If I wanted people to quote the footnotes when replying, I'd
put them before the sig.]

Are you asking about switchable signs in general (the subject of section
1.11 on pages 36-40) or just the blue-background ones? The latter are
not actually featured in the photos.

Well, either, actually. Although it would be interesting to see the
blue-background ones in particular.

As to why they are used, I guess it's either to divert flows in the
peaks to cope with the numbers or because some routes are closed at
certain times, e.g. an exit closed after 23:00.

Interesting guess. Does anyone know?
--
Michael Hoffman