The Great Malvern to Westbury and beyond seem to have a 20 min turn around on arrival at GMV. Even so a number regularly get turned around at Worcester due to late running. This puts pressure on shortening the circuit, say to Gloucester for these services, or even to Parkway.
However, if one builds in too great a turn around then inefficiencies in utilisation of stock and crews start to appear. It is a difficult balance.
With the arrival of the new franchise the Liverpool to Norwich service has been cut into two sections at Nottingham. This is seen as increasing punctuality but at the cost of through journeys for customers.
To what extent are these events being a response to the TOC▸ punctuality requirements?
It's a hugely difficult balance to strike.
Looking back to the summer 1999 timetable, trains from Weymouth only ran as far as Bristol, except for the final service of the day which ran to Swansea on Fridays, Cardiff on Monday to Thursday during the school holidays (joining with a train from Portsmouth at Westbury), and just to Westbury on summer Mondays to Thursdays outside the school holidays. The extension up to Worcester was added to make for better turn around times at Bristol on Weymouth and on Worcester trains, and I think the further extension to Malvern was added when both Wales and West and Central were National Express franchises and the service level needed was, again, one train more efficient using the Wales and West unit rather than the Central one.
Once the services which historically were not linked come together, how much extra traffic is generated? I don't know but unscientific observation suggests that most people change at Bristol Temple Meads. There is no requirement for the service to be joined (
http://gwr.passenger.chat/gwr_slc3b.pdf ) (my bolding of the word "may")
G3
BRISTOL TEMPLE MEADS-CHELTENHAM SPA-GREAT MALVERN
Route Definition
Services may be joined to services specified in Route G1a (Bristol Temple Meads – Taunton), Route G1b (Bristol Temple Meads – Weston-super- Mare) or Route F2b (Bristol Temple Meads – Westbury)
and indeed there is no requirement for them to be joined at Westbury
F4
WESTBURY – WEYMOUTH
Route Definition
1.1 Services shall be provided between Westbury and Weymouth calling at Frome, Bruton, Castle Cary, Yeovil Pen Mill, Yetminster, Maiden Newton and Dorchester West.
1.2 Limited Stops shall be made at Thornford, Chetnole and Upwey.
1.3 Services may be joined to services specified in Route F2b (Bristol Temple Meads - Westbury) or Route F5 (Westbury – Swindon).
In the case of Westbury, there is a considerable volume of "through hub" traffic, and splitting the route there would be much more than an operational matter - it would matter to passengers and should matter to the Community Rail Partnership(s) for the line.
It's not unknown to have a late running Weymouth to Malvern train terminate at Bristol Temple Meads, and an extra train started from there to complete the journey and get the diagram back on time. Through passengers are undoubtedly inconvenienced, though I wouldn't like to put numbers on them; with a change to a Cross Country service, anyone from the Weymouth line to Bristol Parkway or Cheltenham Spa has a fallback train, and passengers for Filton Abbey Wood can probably get a Cardiff train quite soon.
Other splits talked about in the past include all Cross Country services at Birmingham New Street ... now that so much of the really long distance traffic has been lost to air ...
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