The 8.8-km strategic Rohtang Tunnel, being built at 3,000 metre above sea level between Himachal Pradesh’s Manali and Leh in Ladakh, will be opened by September-end. The Rs 3,200-crore tunnel will shorten the 474-km distance between Manali and Leh by 46km, which means the eight-hour journey will be cut by two-and-a-half hours.

The tunnel is also called Atal Tunnel after former prime minister Atal Bihari Vajpayee, who had announced the project on June 3, 2000. The work was entrusted to the Border Roads Organisation (BRO).

The project has faced geological challenges which have pushed the deadline since digging started in 2011. The project was to be completed in February 2015, but water ingress from Seri Nullah, ban on rock mining and delay in allotment of land needed for quarrying, and loose rock strata in the middle caused the slow progress.

Here is everything you need to know about the Atal Tunnel:

• More than 700 men are working in shifts to complete the work of the tunnel. When the coronavirus pandemic-enforced lockdown was imposed, proactive measures were taken to recommence work in active coordination with the state government.

• Defence minister Rajnath Singh was to inspect the work at the tunnel last month, but due to the stand-off between India and Chinese troops, this trip was cancelled. Singh is likely to visit the Rohtang tunnel in at the end of this month.

• The speed limits in the tunnel will be 80km per hour. The tunnel will accelerate troop mobility to strategic frontiers in Jammu and Kashmir, besides providing a road link to Lahaul and Spiti in the winters.

• The tunnel has the capacity to ply 3,000 vehicles per day under any weather condition. The cost of the project has escalated from Rs 1,700 crore in 2010 to almost its double to Rs 3,200 crore by September 2020.

• Himachal Pradesh will run Vistadome buses inside Atal tunnel when it is inaugurated next month. Vistadome buses will have a glass rooftop for a panoramic view through the hilly region.