A groundbreaking high-altitude tunnel, recognized as the world’s longest at an elevation exceeding 3,000 meters above sea level, has significantly reduced travel time by half, cutting through a mountain range. The Tianshan Shengli Tunnel, stretching over 13.5 miles, passes through the Tian Shan Mountain range in the Xinjiang Uygur Autonomous Region of northwest China.
Part of the Urumqi–Yuli Expressway, this five-year project in China aims to enhance connectivity between the mountainous areas of northern and southern Xinjiang. It comprises two parallel tunnels, each accommodating two traffic lanes.
This engineering marvel navigates through the central massif of the Tian Shan Mountains, known as one of Asia’s most complex mountain ranges in terms of topography. The vast mountain range spans over 2,500km, with the tunnel descending to a depth exceeding 1,100 meters beneath the mountain and crossing 16 geological fault zones.
Constructing the tunnel presented various challenges, including extreme temperatures and heavy snow at altitudes surpassing 3,000 meters. Engineers utilized specialized excavation equipment to manage the adverse weather conditions, geological pressures, and seismic activities.
Previously, traversing the region could take hours on hazardous roads susceptible to avalanches and snowstorms. However, travelers can now complete the journey in just 20 minutes, exemplifying the tunnel’s transformative impact.
For instance, the trip from Ürümqi to Korla, spanning about 293 miles by road, which previously took over seven hours, now requires only 3 to 3.5 hours. The Tianshan Shengli Tunnel was inaugurated in December 2025, marking a significant milestone in transportation infrastructure.
According to Song Hailiang, the chairman of China Communications Construction Company (CCCC), the tunnel has set two world records, being the longest expressway tunnel globally and featuring the deepest vertical shaft for a highway tunnel.
Commencing in April 2020, the construction of the expressway involved an investment of 46.7 billion yuan (£5.1bn), with the tunnel constructed at an altitude where temperatures can drop as low as -42°C.
Nurmanat Abdukader, a retired doctor from Pishan county, shared his experience of utilizing the expressway, stating that it reduced his journey home to a single day. This success story follows reports of an undersea tunnel costing £20 billion that could significantly reduce an eight-hour trip to just 40 minutes.
Notably, another ambitious project in China, the Bohai Strait Tunnel, is planned to traverse multiple fault zones over its 123km (76-mile) length, incorporating advanced earthquake-resistant technology. While approximately £20 billion is allocated for this colossal initiative, a definitive completion date has yet to be determined. Nonetheless, Chinese authorities expressed eagerness to commence the project at the earliest opportunity.