"The Prime Minister will inaugurate the Chenani-Nashri tunnel on JK highway on April 2," Union Minister of State in PMO, Jitendra Singh told PTI.
Modi will also address a public rally after the dedication the tunnel project to the nation, he said.
The work on the 9.2 km-long twin-tube tunnel, which is part of a 286-km-long four-lane project on the highway, started on May 23, 2011 in lower Himalayan mountain range, and cost Rs 3,720 crore, officials said.
The tunnel, which is located at an elevation of 1200 meters, will be the first in India to be equipped with world class "integrated tunnel control system" through which ventilation, fire control, signals, communication and electrical systems will be automatically actuated.
It will reduce the travel time between the two state capitals of Jammu and Srinagar by two-and-a-half hours.
The road distance from Chenani and Nashri will now be 10.9 km, instead of the existing 41 km, they said.
IL&FS is all set to handover the tunnel project to National Highway Authority of India (NHAI) soon after its formal inauguration by the Prime Minister.
"The formal trial run was successfully completed for peak, off peak hours between March 9 and March 15," Project Director, IL&FS, J S Rathore said.
Once the tunnel becomes operational, it will reduce the traffic jams on National Highway-1A that occur due to snowfall and avalanches in winter at Patnitop, he said.
Travel will cost an LMV vehicle Rs 55 on one side and Rs 85 for to-and-fro journey and Rs 1,870 for one month travel, while bigger vehicles like mini buses will have pay Rs 90 as one side toll and Rs 135 for to-and-fro toll.
Buses and trucks will have pay Rs 190 as one side toll and Rs 285 as two-side toll.
Rathore informed that Infrastructure Leasing and Financial Services (IL&FS) Company has setup a well-equipped fully computerised operation room for surveillance of vehicles inside the twin tubes.
"For feeding input to the Operation Room, 124 CCTV cameras have been installed at equal intervals of 75 meters, three-tier system has been fitted to light-up the tunnels round the clock," he said.
A SOS system has also been introduced to make contact with the team sitting in the Operation Room in case of an emergency besides effective fire fighting gadgets and hyper-sensitive ventilation system to ensure hassle free journey.
"The maximum speed limit permitted for vehicles plying inside twin tunnel tubes is 50 km per hour with head lights on at low beam. Containers carrying inflammable material are banned from entering the tunnel," he said.
Rathore said maximum height limit permitted is five meters and for checking the height special sensors have been installed just before the toll points at both ends.
"Besides providing mobile network of telecom operators, FM Radio channel facility is also functional inside the tunnel," he said.
The tunnel project involves construction of 9-km-long two lanes (13 metre diameter) of main tunnel along with parallel escape tunnel (6 metre diameter) interconnected with 29 cross passages at 300 meter interval
Rs 27 lakh worth of fuel is likely to be saved per day, he added.
The tunnel will also ensure preservation of pristine forest in ecological sensitive Patnitop area and will provide for better integration of Jammu not only with people of Kashmir but also with Kishtwar, Doda and Bhaderwah by providing better connectivity.