Work to upgrade the Bellarena halt is due to be complete by the end of 2016, Translink have said.
Work started in June and includes a new 800m long passing loop at Bellarena along with two new platforms for six car trains sets.
The work is part of major upgrade to the railway line between Derry and Coleraine at a cost of £46 million.
The original cost was estimated at £20m which then rose to £40m.
The project had been held up at the start of the year because of problems with the contract.
A Translink spokesperson said: “We have been making good progress on night works since June while maintaining normal timetabled services in order to limit disruption to our passengers.
“Working with our contractors McLaughlin & Harvey and Babcock Rail, we are now at the stage of constructing a new 800m long passing loop at Bellarena along with two new platforms for six car trains sets.
“We will also upgrade the signalling and telecomms systems along the railway line ensuring it operates as effectively and efficiently as possible in the future. This work will secure the lines operation for the future and improve on current levels of safety and reliability.”