It's the biggest timetable change in the West Country for a generation, effecting just about every GWR train.
ITV News has obtained details of the heavily delayed plans which are due to go ahead in December.
Over 90 new super-fast trains will replace existing services as part of a £10 billion electrification project.
On some routes, including Cheltenham to Paddington, where the number of journeys on offer will double.
There will also be improvements to Exeter, Taunton and Weston-super-Mare.
Great Western Railway says the new trains will also have 20% more seats, with greater legroom and Wi-Fi throughout.
They will also be more accessible with at least two or four wheelchair spaces and full access to a disabled toilet.
Big improvements will also be seen on much of the network, including between Exeter and Paignton, Exeter and Penzance, and on the Looe and Barnstable branch lines.