In an ideal world this and via Pontyclun would be nice, but either will do.
I agree either will go since a 30 minutely service via Pontyclun would give Pontyclun a train every 15 minutes to Cardiff Central and would help reduce crowding on the Maesteg - Cardiff services.
The downside to that is that it increases congestion on the line between Pontyclun & Cardiff Central which is already struggling now and with proposals for additional freight (TATA have recently submitted plans to build a power station near the steelworks) more capacity will be needed in the future.
The Welsh Government annouced they were going to build a lot of new houses near Cregiau and teh Cardiff West services so re-opening the line via Creigiau is a brilliant idea. A park & Ride interchange at Junction 33 would certainly help the traffic problems along the A4232 into Cardiff.
The only thing I am against if the tram-train option for the route via Creigiau since trains could run beyond Cardiff & St Mellons to Newport and onwards to Severn Tunnel Jct and Gloucester along the relief lines freeing up capacity on the mainlines..
I am interested in seeing how Cardiff Central and Cardiff Queen Street cope with all these proposed extra services, in particular with that bridge over Newport Road just as you leave Queen Street Station heading north. I deally this bridge needs to be replaced with a wider structure and hopefully it will be done in the future if funds become available.
A railink directly to the airport is not a good idea in my opinion especially since all that money has been spent on the express service T9.
Service 905 Rhoose, Cardiff Airport stn - Cardiff Airport/St Athan Enterprise Zone should in the future have an additional vehicle put on and the frequency increased to operate every 30 minutes from 05:30 to 00:00
If all these proposals do come off I think we can all agree things are certainly going to be interesting over the next 3-8 years