Best thing to do is to go to Cardiff Central and buy an Explore Cardiff and Valleys ticket (£13 for the day). Then go to platform 6/7 and wait until one pulls in and see where you end up.

It's possible to take buses between some of the outer termini (Rhymney-Merthyr, Merthyr-Aberdare, Aberdare-Llwynypia/Tonypandy-Bridgend, and Bargoed-Pontypridd are probably the most useful ones [edit: and Coryton-Taff's Well; it's been a while since I've ridden some of these!]), but this will cost extra.

If you only want to do short rides (as far as Llanishen/Coryton/Radyr both ways/Eastbrook/Penarth), then the Explore the Capital ticket at £4.50 is a cheaper option.

I suppose the alternative is the mess caused to the evening peak in South Wales when the 60mph 1300 Theale Murco to Robeston oil empties actually runs (thankfully it's a Q service, so it only periodically makes everything late). I suppose putting in a freight path that doesn't work like this one is the better solution, as its effects are confined to the days that moving tanks full of stale air from Berkshire to Pembrokeshire actually happens.

One thing I have noticed about Brittany is that some quite sensible-looking journeys are basically impossible without a massive detour all the way into Paris and back(!!). There's a perfectly sensible Intercité heading south from Nantes to La Rochelle and Bordeaux, but the train timetable is set up so that the earliest train one can make south from Nantes off an 8.15am ferry arrival at St-Malo is the 1621 (and forget any onward connections from Bordeaux out of that one). I'm not sure why the Intercité route along the west coast doesn't at least routinely start at Rennes, but clearly that would be too helpful for the SNCF^▸ (Societe Nationale des Chemins de fer Francais - French National Railways). This sort of thing makes GWR^▸ (Great Western Railway)'s Cardiff-Portsmouth service look very good indeed.

This is extremely pedantic. The odd Fishguard boat train doesn't really detract from this being an A (if it did, then Reading's a definite B for sake of the Capitals United).

And even before 1931, when passenger services on the former Cardiff Railway were curtailed at Coryton Halt, the terminus of that line was still a halt, viz Rhydyfelin Halt Low Level.

Disappointingly, the weird little branch off the Vale of Neath in Aberdare used the style "crossing" rather than "halt"; otherwise the Black Lion Crossing to Cwmaman Crossing service would have been a service with both termini at halts.

Will that run via Simplon or via Arlberg?

And then you get incidents like yesterday's 1B46 1445 Paddington to Swansea, which really gets busy at Cardiff (and the buffet used to get busy at that point too). Instead the front unit (i.e. the busier one, as the exits at Neath and Swansea are at that end) trolley staff decided they couldn't be bothered to do another run through Standard Class on departure from Cardiff and instead locked it up and went and hid somewhere in First. There doesn't seem to be any sanction from GWR^▸ (Great Western Railway) against this sort of laziness losing them money.

Sounds like a way to make the running into Swansea High Street and reversing even slower than it is now. It's ridiculous that Neath to Llanelli takes as long as Neath to Cardiff. (If only we could do a Plymouth North Road and open a station at Cwmbwrla...)

1. Pilning?

2. The only place I can think of with that configuration of windows/arches is Bristol Temple Meads. Thought it was curvier than that though...

To me the bigger problem is the specification of 51 2-car and 26 3-car units. Seeing as the 3-car 175s are barely adequate and the 2-car ones get horribly overcrowded, to accommodate traffic growth the order should be for 4- or 5-car sets. There is certainly no point in ordering 2-car units.

Surprised no-one's offered Briton Ferry Road yet as the height of the "Road" absurdity. Only about two miles from Briton Ferry, but on the wrong side of the Neath estuary and involving a boat back when it existed (perhaps unsurprisingly, it closed in 1936). I can't imagine any case in which a passenger would ever have chosen to use that station to get to Briton Ferry. Even from the Brecon direction, it would have made more sense to get off at Neath Riverside and either walk over to General station for the South Wales Main Line or get on a bus or (before 1920) tram.

St Mellon's is probably the last place I'd add a local station between Newport and Cardiff (it looks about as promising as Baglan, and for much the same reasons). Splott, Rumney, Marshfield, and Tredegar Park would all be better locations for where people actually live – the estates in the east of Cardiff would be better served by Rumney as it would fit the bus network better. But I'm not sure that feeding anything more into the exercise in excessive compactness that is Cardiff Central is a good idea – if we're doing crayonism, let's have the Taff Vale line descend into a tunnel at Cathays, have its own underground Queen Street station out of the way of the Rhymney line, and then rise up again for Splott.

PRR^▸ (Princes Risborough) = Princes Risborough, I think

Maybe it needs six-tracking like the WCML^▸ (West Coast Main Line), so that TfL can have its equivalent of the DC^▸ (Direct Current) lines to play with, and the Main and Relief lines can be used for trains that at least get west of Reading.