Network Rail Wales and Borders has submitted a business case for the South Wales Relief Line Upgrade (SWRLU).

The upgrade will see better services, connectivity and new stations between Cardiff Central and Severn Tunnel Junction. 

They submitted the proposal to the Department for Transport this month, with the plans highlighting improvements planned for the 27 miles of track and how they plan to refurbish aspects and renew others.

A huge aspect of service improvement also meant that they have requested to increase the speed on the Up and Down relief lines to 100 mph, where possible.

This would allow them to accommodate passenger services, creating more capacity with no extra journey time. Freight trains primarily use these lines, and the speed increase would allow better efficiency for those services.

The approval of upgrades to the infrastructure is crucial to the second half of their plan, which would see six new stations built, including Cardiff East, Newport West, Somerton, Llanwern, Magor & Undy, and Cardiff Parkway.

If the plans are approved, the project will move into official planning and design before delivery can begin.

“The South Wales Relief Line Upgrade is a vital step towards delivering better rail services for communities and businesses across South East Wales. By increasing the speed and capability of the relief lines between Cardiff and Severn Tunnel Junction, we can create the capacity needed to support new passenger services and unlock the proposed new stations along this route. 

“We’re proud to be working closely with Transport for Wales to enable improved connectivity, support sustainable travel and make it easier for people to access the railway in the future.” 

Nick Millington, route director for Network Rail Wales and Borders