Chinese authorities have officially opened the 22-kilometer-long Tianshan Shengli Tunnel in the northwest of the country, Xinhua news agency reports.

According to the Chinese side, this is the world's longest expressway tunnel.

Traversing the central Tianshan Mountains in northwest China's Xinjiang Uygur Autonomous Region, the tunnel slashes what was once a several-hour mountain drive to just 20 minutes.

As a vital artery linking city clusters in northern and southern Xinjiang, the G0711 Urumqi-Yuli Expressway, including the tunnel, entered operation on the same day.

The expressway, constructed over five years, spans 324.7 kilometers with a total investment of 46.7 billion yuan (about 6.63 billion US dollars).

It reaches a maximum burial depth of 1,112.2 meters, crosses 16 geological fault zones and faces five major difficulties—high ground stress, high seismic intensity, stringent environmental requirements, extreme cold and high altitude.