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, they will help to boost local employment opportunities.
More top news
Andrew Lauder, from Wenvoe, south Wales, has been branded a "serial groper".
The deal is welcome news for the site in Broughton which manufactures wings for the aircraft.
Fans queued for hours to get a glimpse of the Royal Couple as they tour Cardiff Castle and visit a community centre.