Network Rail has nearly finished work on the £48M Loughor Viaduct and railway line redoubling project near Swansea.
The redoubling project, which relates to an 8.4km long stretch of railway, has been funded by the Welsh Government and South West Wales Integrated Transport Consortium.
The line between Swansea and Llanelli will be closed for 16 days up to 8 April while the work is finalised. The aims of the project are to increase capacity and improve the frequency and reliability of trains.
“Better links between communities mean better access to employment, education training and leisure opportunities which is a key aspect of tackling economic and social deprivation, so I am delighted that the Welsh Government has contributed £25M to these improvement works,” said Welsh transport minister Carl Sargeant.