That's an interesting point, and one I did think about when I discovered my normal 1730 was cancelled. If the train is rammed to the point that no-one else can get on, do the on train staff have any right to ask pax for Chippenham to get off the train to enable those for Melksham and beyond to get on? It would seem a sensible thing to do, but I can imagine the problems it could cause.
That's a "special case" concern, thank goodness. The train is scheduled to leave six minutes after your "Taunton" (17:30
HST▸ ex Swindon via Chippenham) and as a result the local traffic from Swindon to Chippenham on the service is sparse on the 17:36. It's how we wanted it to work - self policing, if you like - whether by design (
FGW▸ have some clever and thoughtful timetables) or otherwise, it works.
On days like the one we talk about - I don't know; at it happens I was at Chippenham rather than Swindon to join, but I can imagine heated incidents if asking people to get off so that longer distance traffic could get on. We actually have had a very real fear that - were a successful station to be opened at Royal Wootton Bassett while the TransWilts is limited to a single carriage 8 trains per day that it would overcrowd off Swindon and deny boarding to passengers for beyond - however, "RWB" looks like it's one of the later / less likely prospects on the
http://www.transwilts.org TransWilts vision 2020 map.
I doubt whether the service was any busier than usual south of CPM» due to the earlier cancellation, so 'full and standing" is probably just the norm now for that service.
Passengers for the 17:30 would have been well advised to wait for the train that's half an hour later for Bath Spa, and for Bradford-on-Avon via Bath Spa. For Bristol and beyond, travel via Parkway may have regained them some time. The only stations that are quicker via Melksham if the 17:30 is cancelled are Avoncliff and Freshford, and the flows from Swindon or Chippenham to those two aren't significant.
On the other hand, passengers from east of Swindon onto the 17:36 are given the 17:30 into Swindon as their connecting service, so south of Chippenham the service was a little quieter than usual; I noted the absence of a couple of regulars who I happen to have got to know, and there may have been more. But for sure "full and standing" is the norm for this service into Melksham; there are enough seats for everyone who's left on board south of there.