The first phase of night-time improvement works which have been taking place on the Lisburn to Portadown railway line are due to be completed on schedule on March 26.
A total of 21 miles of track will be repaired, 10.5 miles in each direction, during the entire project.
The first phase, with contractors McLaughlin and Harvey, has involved the removal and replacement of ballast stone under 3 miles of track between Lisburn and Moira.
The programme of works, when complete, will maintain the reliability of the line, remove speed restrictions to facilitate trains operating at 90mph on parts of the track, a more comfortable passenger experience with a smoother ride, reduced need for on-going essential engineering works and improved drainage.
This work forms part of a £25m project funded by the Department for Infrastructure, with support from the Connecting Europe facility.