A major rail timetable change will see train times change significantly in December, allowing for increased services at some stations, later services from Cardiff Central and Swansea, trains leaving at the same time past each hour and more new trains.

The changes are possible because of the enhanced capabilities of the brand-new Class 197 train fleet which has been replacing older trains over the last two years.

It has been described as the “most significant mainline timetable change in a generation” and has taken four years to develop.

Customers across South Wales and the Marches will need to keep a close eye on the times they travel as every mainline service will be retimed.

The timetable change comes into effect from Sunday 15 December, and customers are urged to check before they travel.

Changes to the timetable will also impact other operators within Wales and the borders.

Some key changes within the new timetable include:

Significantly more stops at Pontyclun, Llanharan and Pencoed – increase in total daily services from 38 per day to 59. A 55% increase.

Increase in Swanline services during peak hours to 1 train per hour (Baglan, Briton Ferry, Skewen and Llansamlet).

Two extra Milford Haven services and a more evenly spaced service to Fishguard Harbour which removes a six-hour gap without trains during the middle of the day.

The last train from Cardiff to Maesteg via Bridgend is now later – at 11:24pm.

Later last train from Swansea to Cardiff leaving at 11:30pm Monday to Friday.

More consistent departures with more trains leaving at the same time past each hour.

Maesteg services towards Cardiff will now run through to Ebbw Vale, rather than Cheltenham Spa.

Cheltenham Spa services will start and end at Cardiff Central.

Instigation of the changes brought about by the Strategic Timetable Review on the Cambrian and Heart of Wales lines.

Introduction of brand new Class 756 trains on the Core Valley Lines (starting November) and dedicated active travel trains with extra bike spaces, a full refit and a dedicated livery for the Heart of Wales line.

Some changes to the calling pattern on certain services between Cardiff and Manchester Piccadilly, to speed up some trains and deliver a standard pattern in the timetable.

Some local services between West Wales and Cardiff will now use Platform 0 at Cardiff Central.

The North Wales Branches will continue to have 100% of journeys on new fleet and the North Wales Mainline with over 80% of journeys on new fleet. Overall, over 87% of journeys will be on new fleet for North Wales services from December 2024 timetable.

Cabinet Secretary for Transport and North Wales Ken Skates said: “This is a major change which will make a real difference to customers, who will benefit from a more consistent service. This has been made possible by our £800m investment in new trains and it’s great to see the results coming through across Wales.”

Transport for Wales’ Planning and Performance Director Colin Lea said: “This is the most significant timetable change in a generation for mainline services.

“We’ve invested £800 million in new trains and now is the time to really make the most of them. We’ve been working towards this timetable for four years and the consistency it will deliver will be a massive improvement for many customers.

“While this is a major change, there are also big improvements planned for the North Wales Coast and Cambrian lines in the next 18 months with newer trains and capacity improvements.”

Nick Millington, Network Rail Route Director for Wales & Borders, said: “This timetable change is going to be significant with faster journeys, more frequent train services and more seats across our network.

“Our passengers depend on services to get them to where they need to go and these changes are all part of building a better, more reliable, and sustainable railway as we work in partnership with Transport for Wales to deliver the best for Wales & Borders.”