The 1,000 mm (3 ft 3+3⁄8 in)-wide metre-gauge railway earlier laid by Assam Bengal Railway from Chittagong to Lumding was extended to Tinsukia on the Dibru–Sadiya line in 1903.[1][2]
The project for the conversion of the Lumding–Dibrugarh section from metre gauge to 5 ft 6 in (1,676 mm) broad gauge was completed by the end of 1997.[3]
The 123-kilometre (76 mi)-long Dimapur–Zubza–Kohima new line project has the status of a National Project. Final location survey has been completed for the entire project.[8][9]
As of August 2019, the 25% work on the 82.5 km line from Dhansiri to Zubza near state capital Kohima has been completed, railway has requested the Nagaland govt to expedite the land acquisition process which is holding up progress on this rail link.[citation needed]