"Paul Scott" writes:

Touching out and touching straight back in at the same station doesn't
necessarily end and restart a new journey, and there are logical reasons for
this. Once a journey that has been joined to another goes beyond the time
limit (and that limit is variable dependent on zones crossed) the first part
of the journey becomes 'uncompleted' and the latter part 'unstarted'. This
is charged as two 'maximum cash fares' and doesn't contribute to the daily
cap.

So would it not make more sense to only combine them if the combined
journey is within the time limit for the overall journey and keep them
as separate journeys[1] if the combined journey would be over the time
limit. Also, always treat it as 2 separate journeys rather than
combining them where someone touches in at A, touches out at B, then
later touches in again at B travels to A and touches out.

[1] As long as the time between between each touch in and the next touch
out is within the time limit.