As many as 14 tunnels, all double-tube, are to be built on the highway as part of its conversion into a four-lane highway.
Tunnelling of 1,245 mtr-long tunnel between Malori and Nela, which will bypass the Mandi town, has been completed. The first tunnel was completed on 13 May 2022.
The second tunnel, the work on which commenced in May 2019, was also completed on 13 June 2022.
The tunnelling work will be completed in a few months and will be handed over to NHAI by February 2023. A large number of major and minor bridges and tunnels are being constructed in four-laning of the NH-3.
Once complete, the project will reduce the travel time between Chandigarh and Manali from nine to10 hours to nearly seven hours.