CARMARTHEN'S rail links are set to improve after a £48 million upgrade to a section of the line to Swansea.
The Network Rail project to replace the Loughor Viaduct and redouble a 5.25-mile stretch of railway through Gowerton opened on Monday.
On the back of this work, which removed a bottleneck caused by the old single line, Arriva Trains Wales has announced extra services and more carriages starting from May 19.
All single-car trains on the Swansea — Carmarthen — Pembroke Dock route will be replaced with two carriage trains, doubling capacity on the route.
A Cardiff to Swansea 'Swanline' service is extended to Llanelli, departing Swansea at 16.23. It will provide additional capacity and a new commuter departure from Swansea in the evening peak period.
Mike Bagshaw, commercial director for Arriva Trains Wales, said: "These changes are good news for passengers in West Wales.
"We regularly review our services in partnership with the Welsh Government, other key stakeholders and by listening to our customers.
"Many passengers, including commuters and visitors to the area, will see real benefits from this package of changes."
The line upgrade project was jointly funded by Network Rail and the Welsh Government in partnership with the South West Wales Integrated Transport Consortium (SWWITCH).
Mark Langman, route managing director, Wales, said: "The difficult and exciting task of replacing the Loughor Viaduct is now complete and progress with the redoub- ling of the five-mile stretch of line is going to plan.
"This new viaduct and redoubling of the railway through Gowerton will remove the current bottleneck created by the stretch of single line and provide capacity to run more trains in the future.
"This project joins a number of other rail improvement projects in South and West Wales that will help deliver better journeys and boost economic growth in the area.
"As well as making it easier to travel to and from West Wales, it will help to boost local employment opportunities.
"I would like to thank people for their patience while we have worked to improve the viaduct and lay the second track."