Though, for me, the word 'circulate' is a bit of a silly one to give to passengers.
I agree with the sense in having passengers go through and return to get to their station when it's only open / there's only a train calling in one direction. As well as at times of stress to the system (where the platform one direction is closed), it's allowed routinely under easements of routing for places where it makes journeys more practical - see via
http://data.atoc.org/routeing-guide and search the easement list for places like Dilton Marsh and Pilning.
But I struggle with what to call this for the public. I too have some disquiet at the word "circulate". I too imagine passengers dressing finely and partaking of a cheese and wine party on the transfer bridge at Reading, mixing with
GWR▸ and Network Rail managers as they make an unexpected stop on their way home from London to Slough.
But all very easy to criticise - but what wording would be better??"Divert via" ... does not indicate the passage through the target station during the round(dish) trip, and I think there's a need for the passenger to be aware this will happen - otherwise the passenger will get concerned and may pull the emergency chain (or whatever it has been replaced with.
"Circulate via" ... see my comments above
"Reflect at" ... oh dear -
- I can imagine the idea relaxation classes, meditation groups ....
"passing through your planned destination to come back the other way" ... too long for short messages and
CIS▸ screens
"Double Back at" is the wording used in the routing guide. To me that's good, clear enough, and strikes me as a positive change from "circulate" - but would it be understood by the public?