But the NR study said the aim was for 1tph to each, not tomorrow but in 2040 or something, so there is no harm hypothesising about future travel. I’m not 100% Bristol TM needs 4tph but it’s happening and future growth is antipated. No idea why people are so defensive about it, when ‘build it and they will come’ is proven, especially with direct London rail services and suppressed demand, which I’d say Cheltenham suffers from.
This would also give Newport and Cardiff a third TPH to London (slower but probably cheaper), add capacity for the local journeys, new direct London services for places (Chepstow could be a great tourist centre, castle, races, all the Wye towns/castles) and add a higher quality service from Western England into South Wales. It seems to have so many benefits, whereas a train terminating at Gloucester and returning to London doesn’t quite have as much purpose.