I've travelled on almost all the cited lines in Northern Britain and note that none of them would probably justify construction on the basis of current traffic levels.
I've been encouraged to see the success of the Borders and Ashington lines, both of which have absorbed massive amounts of capital expenditure and will require operational subsidies for the foreseeable future. In both cases the world has moved on since the original railways were built 150-200 years ago and they're serving almost completely different markets.
That's the underlying issue for most of today's railways. Original and current purpose. I live close to the Midland Mainline and the 'mainline' between Sheffield and Manchester. The MML is and was primarily a fast passenger railway. Both the Hope Valley and Woodhead routes were built primarily to haul slow and long loads of coal from east to west.
I look at Stranraer station today and it's a sorry sight. 100 years ago my grandfather regularly took a connecting boat train from Newcastle via Dumfries for the ship from Stranraer for business in Belfast and Ireland. At that time a lot of Irish migrants to Tyneside would do the same. It was similar for large numbers living in lowland Scotland. Boats and trains were the natural way to go. I have a picture from the 1950s of my aunt and uncle standing beside their car for it to be flown to Ulster. The world was moving on fast. We'd got steadily wedded to our cars.
If we didn't use cars flights from Newcastle, Edinburgh and Glasgow were becoming available to Belfast, Dublin and Cork. The ferry terminals have moved to Cairnryan making the remaining railway useless for its intended purpose.
The remaining rail need is very modest and could be more frequently and more cheaply served by bus - a bus that would share use of the not terribly good roads, but they've improved a lot since the old track-bed from Carlisle got repurposed (I'll avoid diving down the Boris tunnel/bridge to Ireland rabbit warren!)
I would never accept the statistics found on the Railway Data website for Stanraer as totally accurate but from my own observation they seem to provide quite a good guide for the Girvan - Stranraer section; see;
https://www.railwaydata.co.uk/loadings/gbr/?TLC=STR
Click on train numbers to see progress of each train.
These results represent an average weekday during the Summer 2024 timetable.
TRC | TOC | Origin | Arr | Dep | Destination | Board | Alight | Through |
| SR | Originates | | 07:04 | Glasgow Central | 2 | 0 | 0 |
| SR | Ayr | 08:53 | | Terminates | 0 | 5 | 0 |
| SR | Originates | | 09:00 | Ayr | 39 | 0 | 0 |
| SR | Ayr | 12:57 | | Terminates | 0 | 35 | 0 |
| SR | Originates | | 13:05 | Ayr | 24 | 0 | 0 |
| SR | Ayr | 16:56 | | Terminates | 0 | 14 | 0 |
| SR | Originates | | 17:07 | Ayr | 2 | 0 | 0 |
| SR | Kilmarnock | 18:57 | | Terminates | 0 | 14 | 0 |
| SR | Originates | | 19:08 | Kilmarnock | 2 | 0 | 0 |
| SR | Kilmarnock | 23:00 | | Terminates | 0 | 3 | 0 |
I'm just back from Inverness, another story. I first visited in 1958 on the way to Skye. It's changed a lot.