From: johnl@iecc.com   
      
   >> Depends whose rules.  Guiness does not require a single fare, probably   
   >> because the London challenge doesn't either.  (I don't think you can   
   >> do London in one fare.)   
   >   
   >How sad. Which lines are disconnected from which? Does the new all-night   
   >service on weekends on one or two lines change that? (Maybe it's just   
   >a matter of time that keeps them from doing it all in 18 hours or so.)   
      
   I asked the TfL nerds at uk.transport.london, and the consensus was   
   that you couldn't do the whole system on a single fare between the   
   time it opens in the morning and closes at night.  The new night tubes   
   may change that, but nobody has figured out a route plan yet.   
      
   The Underground uses a zoned fare system with time limits per trip, so   
   even if you did it without leaving the system, you'd still need a   
   multiday travelcard in case you met a fare inspector.  A fair number   
   of Underground stations are ungated; you touch in and out as you enter   
   and leave, but there's no physical gate or turnstile to pass through.   
   Hence you are required to have valid payment with you and sometimes   
   they check.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)