A groundbreaking project in China has resulted in the construction of the world’s longest high-altitude tunnel, situated at an impressive altitude of over 3,000 meters above sea level. The Tianshan Shengli Tunnel spans a remarkable 13.5 miles, effectively reducing a seven-hour journey by half as it cuts through the Tian Shan Mountain range in Xinjiang Uygur Autonomous Region.
This engineering marvel, a part of the Urumqi–Yuli Expressway, is a significant endeavor aimed at improving connectivity between the mountainous regions of northern and southern Xinjiang. It comprises two parallel tubes, each capable of accommodating two lanes of traffic.
The tunnel’s construction involved overcoming the challenges posed by the intricate terrain of the Tian Shan Mountains, known for their complex topography in Asia. Stretching over 2,500km, the tunnel descends to depths exceeding 1,100 meters beneath the mountain, traversing 16 geological fault zones.
Working in extreme conditions at altitudes above 3,000 meters, laborers had to contend with severe temperatures and heavy snow. Specialized excavation equipment was utilized by engineers to address the harsh weather conditions, geological pressures, and seismic activities.
Previously, travelers navigating through the area faced perilous journeys on hazardous roads susceptible to avalanches and snowstorms, enduring hours-long trips. However, with the completion of the tunnel, the same journey can now be completed in just 20 minutes.
An illustration of the tunnel’s impact is seen in the route from Ürümqi to Korla, covering approximately 293 miles by road. What was once a journey of over seven hours now reportedly takes only 3 to 3.5 hours.
The Tianshan Shengli Tunnel was inaugurated in December 2025, setting two world records according to Song Hailiang, chairman of China Communications Construction Company (CCCC). Song stated to state broadcaster CCTV that the tunnel is the longest expressway tunnel globally and features the deepest vertical shaft for a highway tunnel.
Construction of the expressway commenced in April 2020, with an investment of 46.7 billion yuan (£5.1bn). The tunnel was constructed at an altitude where temperatures can drop as low as -42°C.
Nurmanat Abdukader, a retired doctor from Pishan county, shared his experience with China Daily, mentioning that the tunnel significantly reduced his travel time, allowing him to complete his journey home in a single day. This success story follows reports of an underwater tunnel project costing £20 billion that aims to cut an eight-hour journey to just 40 minutes.
In China, another ambitious project, the Bohai Strait Tunnel, is set to traverse multiple fault zones along its 123km (76-mile) length. The tunnel is planned to incorporate advanced earthquake-resistant technology.
With a substantial budget of £20 billion allocated to the massive undertaking, a specific completion date for the Bohai Strait Tunnel has not yet been established. However, Chinese authorities expressed their eagerness to initiate the project “as soon as possible” back in
