In article ,
wbriscoe@nospam.demon.co.uk (Walter Briscoe) wrote:

> I believe the logic is: up to 15 minutes - an in-zone fare; more 
> than 15 - the charges for an unfinished journey and an unstarted 
> journey. I am unsure about the boundary condition. I have not got 
> very far trying to persuade TfL that this behaviour needs to be 
> documented.

Time for a Freedom of Information request then?

-- 
Colin Rosenstiel