Do local trains REALLY cost a lot to run?

[whole diary]

[Trowres]

Surely the cost of any such work is borne by Network Rail who recover their investment in increased track access charges generated by the increased usage of that stretch of line.
If their is no increase in usage then not too sure you would bother.
I would also hope that stoppers are always timetabled to follow expresses.

Thanks for your comment, to which I will now attempt a reply.

To keep it simple, I don't think it's necessary to worry about how the scheme is financed (in your case by NR^» (Network Rail - home page) borrowing). The crucial thing is the balance between the following possible outcomes:
a) No loop, infrequent stopper, infrequent IC^▸ (Inter City) at full speed
b) No loop, frequent services, IC runs slower
c) No loop, frequent IC at full speed, no stopper
d) Loop, frequent IC at full speed, frequent stopper
So, the cost of the loop could be offset by the following benefits, depending upon which "do nothing" case you choose:
a) more frequent IC and stopper
b) Increased speed of IC service
c) Having a frequent stopper against having no stopper at all.

Did I say keeping it simple? Please bear with me...

Now, benefits a, b and c are probably different in economic and social value, and not all may be sufficient to cover the cost of the loop with a bit to spare (the 2.0 BCR^▸ (Benefit Cost Ratio) for infrastructure schemes implies quite a bit to spare).

Which of a, b and c would be taken as the baseline? It's often down to a quirk of history - which service started first, or which was not shut down by Beeching.
Often, it's case c as the fast, frequent IC service is a "given". So its the local train that has to be weighed up against the cost of the loop. How often is the question asked: We could do without the loop if the IC runs 2 minutes slower. Is the benefit of saving this time worth the cost of the loop?  I don't know...maybe the question s there in the RUS^▸ (Route Utilisation Strategy) programme rather more than in popular debate.

On your last point, Andy, yes the stopper would start off from a station just behind the fast train. Depending on the length of route, it may be caught up by the following fast train (which is why the need for a loop depends on the frequency of trains as well as their relative speed).

[eightf48544]

An interesting analysis Towres , but the problem seems to be that you are still looking at th micro economics of should we build a loop at X. Rather than the macro effect on the route as whole.

For instance if Wantage Road or Uffington or a new station in between were to be reopened than I would expect them to be on loops with the possibily of extra4 tracking between Didcot and Swindon as well.

Now if you throw in flyover at Wotton Bassett and reinstating the third platform at Chippenham with bi-directional working on teh current Down Line then you can invisage Bristol Oxfords and Didcot Westbury/Salisbury stoppers via Melksham. Reinstate  the Bradford on Avon North Curve and wow the possibilites are endless.

With the current system it is very difficult to justify these schemes on their own merits they only make sense as a total plan the cost of which would scare the Treasury to death. We need a new Brunel with vison, all his projects bust their budgets but look at his legacy if it's only the GWML^▸ (Great Western Main Line).