A groundbreaking high-altitude tunnel, celebrated as the world’s longest at over 3,000 meters above sea level, has significantly reduced travel time by cutting a seven-hour journey in half through a mountain range. The Tianshan Shengli Tunnel, spanning 13.5 miles, pierces through the Tian Shan Mountain range in northwest China’s Xinjiang Uygur Autonomous Region.
This ambitious project, part of the Urumqi–Yuli Expressway, is a five-year endeavor aimed at enhancing connectivity between the mountainous regions of northern and southern Xinjiang. The tunnel comprises two parallel tubes, each capable of accommodating two traffic lanes.
Engineered as a remarkable feat, the tunnel traverses the central massif of the Tian Shan Mountains, known for being one of Asia’s most intricate mountain ranges in terms of topography. With the mountain range stretching over 2,500km, the tunnel descends to a maximum depth exceeding 1,100 meters beneath the mountain and passes through 16 geological fault zones.
Workers faced extreme challenges due to harsh weather conditions at altitudes surpassing 3,000 meters, including heavy snowfall. Specialized excavation equipment was employed by engineers to contend with the adverse weather, geological pressures, and seismic activities.
Previously, travelers navigating the region encountered perilous roads susceptible to avalanches and snowstorms, resulting in hours-long journeys. However, with the completion of the tunnel, the same trip now takes only 20 minutes.
An illustrative example of the tunnel’s impact is the route from Ürümqi to Korla, approximately 293 miles by road. Previously requiring over seven hours, the journey now reportedly takes around 3 to 3.5 hours.
The Tianshan Shengli Tunnel was inaugurated in December 2025, setting two world records, as stated by Song Hailiang, chairman of China Communications Construction Company (CCCC). Song highlighted that the tunnel holds the titles of the world’s longest expressway tunnel and the deepest vertical shaft constructed for a highway tunnel.
Initiated in April 2020, the construction of the expressway received an investment of 46.7 billion yuan (£5.1bn), with the tunnel being constructed at an altitude where temperatures can plummet to as low as -42°C.
A retired doctor, Nurmanat Abdukader from Pishan county, shared his experience with China Daily, mentioning that the tunnel reduced his travel time to a single day. This success story echoes reports of an undersea tunnel costing £20 billion, which slashed an eight-hour journey to a mere 40 minutes.
Furthermore, in China, the proposed Bohai Strait Tunnel is anticipated to traverse several fault zones across its 123km (76-mile) length, incorporating earthquake-resistant technology. Although a significant budget of £20 billion has been allocated to this colossal project, a definitive completion date is yet to be determined. Nonetheless, Chinese government representatives expressed eagerness to commence the project “as soon as possible.”
