Photo taken on Oct. 15, 2014 shows the Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the tunnel, with a length of 7,079 meters, is expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]

Photo taken on Oct. 15, 2014 shows the Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the tunnel, with a length of 7,079 meters, is expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]

Photo taken on Oct. 15, 2014 shows the infirmary of Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the Chola Mountain Tunnel, with a length of 7,079 meters, is still under construction and expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]

Photo taken on Oct. 15, 2014 shows the staff canteen of Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the tunnel, with a length of 7,079 meters, is still under construction and expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]

Photo taken on Oct. 15, 2014 shows the staff's play-room of Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the tunnel, with a length of 7,079 meters, is still under construction and expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]

Photo taken on Oct. 15, 2014 shows the staff's play-room of Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the tunnel, with a length of 7,079 meters, is still under construction and expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]

Photo taken on Oct. 15, 2014 shows a staff dormitory of Chola Mountain Tunnel, world’s highest super long road tunnel in Derge County of Garze Tibetan Autonomous Prefecture, southwest China’s Sichuan Province. Launched in September 2012, the tunnel, with a length of 7,079 meters, is still under construction and expected to be completed in 2017. As a key project along the National Highway 318, it will enable vehicles to take ten minutes to pass through the mountain. [Photo/Cri.cn]