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 cutting a seven-hour journey in half through a mountain range. Extending over 13.5 miles, the impressive Tianshan Shengli Tunnel carves its way through the Tian Shan Mountain range in the Xinjiang Uygur Autonomous Region of northwest China.
This major project, part of the Urumqi–Yuli Expressway, is a five-year endeavor aimed at enhancing connectivity between the northern and southern mountainous regions of Xinjiang. Comprising two parallel tubes, each capable of accommodating two lanes of traffic, the tunnel represents a remarkable engineering achievement, navigating through the central massif of the Tian Shan Mountains, one of Asia’s most intricate mountain ranges in terms of topography.
Covering a vast expanse of over 2,500 kilometers, the tunnel descends to a depth exceeding 1,100 meters beneath the mountain surface and traverses 16 geological fault zones. Constructing the tunnel posed significant challenges, with workers contending with extreme temperatures and heavy snow at altitudes surpassing 3,000 meters. Specialized excavation equipment was employed by engineers to manage the adverse weather conditions, geological pressures, and seismic activities.
Previously, journeys through the region could be arduous, taking hours on hazardous roads susceptible to avalanches and snowstorms. However, travelers can now complete the trip in just 20 minutes, exemplifying the transformative impact of the tunnel. For instance, the journey from Ürümqi to Korla, spanning approximately 293 miles by road, which used to require over seven hours, now takes an estimated 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 highlighted that the tunnel is the longest expressway tunnel globally and features the deepest vertical shaft in a highway tunnel.
Commencing in April 2020, construction of the expressway entailed an investment of 46.7 billion yuan (£5.1bn), with the tunnel constructed at an altitude where temperatures can plummet to as low as -42°C. A retired doctor from Pishan county, Nurmanat Abdukader, recounted how the tunnel had streamlined his journey home to a single day, underscoring its positive impact on travel efficiency.
In China, plans for the Bohai Strait Tunnel, spanning 123 kilometers (76 miles) and intended to traverse multiple fault zones, are underway. The project, which is anticipated to integrate earthquake-resistant technology, has an estimated budget of £20 billion, although a definitive completion date has yet to be established. Despite this, Chinese authorities expressed eagerness in 2018 to expedite the project launch.