Network Rail has completed 12 weeks of major improvement work to the railway in Northamptonshire as part of the Midland Main Line upgrade.
The work saw two of four rail lines closed to allow Network Rail engineers to carry out major work to track, drainage, bridges and viaducts in the county.
During the work, 57 engineering trains were used to install four kilometres of new track, more than half a kilometre of track was renewed and more than 300 tonnes of ballast, the stones which support the track, was laid.
Irchester and Wellingborough viaducts and Sharnbrook Tunnel were strengthened and repaired and Halsey Road bridge in Bedford was demolished and reconstructed to support increased rail traffic which will use the additional and existing lines in the future.
While a major milestone has been reached, work continues on the Midland Main Line upgrade in Northamptonshire as Bush bridge, Finedon Road bridge and Station Road bridge in Wellingborough continue to be reconstructed.
Network Rail and East Midlands Trains worked together to keep passengers moving throughout the work.
Ed Akers, principal programme sponsor at Network Rail, said: “We’d like to thank passengers for their patience whilst this vital upgrade was carried out and apologise for any disruption this caused.
“We’ve worked closely with East Midlands Trains to keep this to a minimum.
“Whilst this major milestone has been reached, we are still continuing with work in the county as part of the Midland Main Line Upgrade.
“This work will see three bridges reconstructed to allow electrified wires to be positioned safely beneath them and we look forward to passengers seeing the benefit once this work is completed.”