MIG wrote

A question (relating to "Bob" in another thread).

Is it possible for a ticket office to terminate a journey for you, eg
when you are in an OSI but want to start a new journey, either with a
long timeout or it's now off peak but wasn't when the first journey
started?

You can always force a new journey by touching in on a bus !

It would be handy if you could do this on a ticket machine too.

Now my draft explanaion of OSIs
===========
As you know Bob, in Britain fares work differently on buses and trains,
on a journey by bus each bus taken is a separate fare, but on trains
and underground you are charged a fare for the whole journey even if
you have to change en route.

In the usual case when you never go through an exit barrier until your
journey is complete Oyster's only difficulty in working out the proper
fare on trains and underground is deciding what route you took but, for
example when changing between rail and underground, you will often go
though an exit barrier then a little later go through an entrance gate
to continue your journey.
In some case this may involve crossing the street to a station with a
different name or to a different part of the same rail or underground
station but in all such cases Oyster must recognise that a jouney is
not ending but continuing Thus for this purpose the Euston - Kings
Cross - St Pancras interchange consists of three rail stations and
three underground stations (because of Euston Square) and the Victoria
interchange is two barriered rail stations - Victoria (Southern) &
Victoria (SouthEastern) plus an underground station..

If at one of these interchanges (Out of Station Interchanges, OSIs) you
pass through another entrance gate within the specified time allowance,
say 20 minutes, the journey is regarded as continuing. After that time
or if you touch in on a bus or go to some other station that ends the
old journey.

====

Critics, please remember we want to leave out as much detail as
possible and just get the concept over. I don't want to mention /here/
that Kings Cross (Metropolitan) still counts as yet another underground
station nor that some stations don't have barriers, only validators and
so forth.