Prime Minister Narendra Modi today inaugurated the strategically important, all-weather Atal Tunnel in Himachal Pradesh that connects Manali to the Lahaul-Spiti valley and reduces travel time to Leh (in the Union Territory of Ladakh) by up to five hours.Prime Minister Modi was accompanied by Defence Minister Rajnath Singh and Himachal Chief Minister Jairam Thakur.Described as the longest highway construction of its kind in the world (above 10,000 feet), the 9.02 km-long Atal Tunnel is built to “ultra-modern specifications” at an altitude of 3,000 metres (10,000 feet) in the Pir Panjal range of Himalayas.It is a horse shoe-shaped, single-tube, double lane tunnel with a roadway of eight metres and has an overhead clearance of 5.525 metres, the Prime Minister’s Office said in a statement.The tunnel has been designed for traffic density of 3,000 cars and 1,500 trucks per day, each of which can travel at a maximum speed of 80 kmph.The south portal (SP) of the tunnel is located at a distance of 25 km from Manali and at an altitude of 3,060 metres. The north portal (NP) is located near the Teling village in the Lahaul Valley at an altitude of 3,071 metres.The decision to construct a strategic tunnel below the Rohtang Pass in Himachal was taken on June 3, 2000, when Atal Bihari Vajpayee was Prime Minister. The foundation stone for the access road to the South Portal was laid on May 26, 2002.The Union Cabinet decided in 2019 to name the Rohtang Tunnel as Atal Tunnel to honour the contribution made by the former Prime Minister.The Border Roads Organisation (BRO) worked relentlessly to overcome major geological, terrain and weather challenges that included the most difficult stretch of the 587-metre Seri Nalah Fault Zone. The breakthrough from both ends was achieved on October 15, 2017, the PMO’s statement said.