A 319.7-kilometer expressway in the Xinjiang Uygur autonomous region is set to open by the end of December, regional transport authorities announced.

The route features the 22.13-km Tianshan Shengli Tunnel, the world's longest expressway tunnel, cutting through the east-west Tianshan Mountains across Xinjiang.

The expressway links the regional capital Urumqi, north of the mountain range, with Yuli county in the Bayingolin Mongolian autonomous prefecture to the south. Its main line includes 265 bridges and 17 tunnels. Construction began in 2019.

Once opened, crossing the Tianshan Mountains via the Shengli tunnel will take about 20 minutes. Travel time from Urumqi to Korla, a major city in Bayingolin, will be cut from seven hours to roughly three.

Guo Sheng, Party secretary of Xinjiang's transport department, said the expressway will ease long-standing traffic bottlenecks that have constrained coordinated development between northern and southern Xinjiang.

He said key technological breakthroughs achieved during construction of the Tianshan Shengli Tunnel- an ultra-long highway tunnel built in high-altitude, cold mountainous conditions — will offer valuable experience for tackling similar transportation challenges elsewhere.

Improved road connectivity is also expected to boost tourism. Liu Heping, head of Bayingolin's tourism association, said local authorities, scenic sites, hotels and other tourism-related partners are preparing for an anticipated surge in visitors to the prefecture, which is known for attractions such as the Bayanbulak Grassland and Bosten Lake.

The Bayanbulak National Nature Reserve in Hejing county was added to UNESCO's World Heritage List in 2013 as part of the Xinjiang Tianshan property.

Guo said several additional north-south transport projects began construction earlier this year, including a railway linking the cities of Yining and Aksu and an expressway connecting Kuitun, Dushanzi district of Karamay, and Kuqa.

Over the past decade, Xinjiang has made notable progress in building an integrated transport system, with improvements in infrastructure networks, service quality, operational efficiency and safety, he said.

According to the region's transport department, Xinjiang's rail network spans 9,557 km, connecting all 14 prefecture-level regions and more than 80 percent of county-level administrative areas.

Xinjiang's total road network is expected to reach 237,000 km by year's end. All county-level administrative areas — except Tashikurgan Tajik autonomous county and the newly established He'an and Hekang counties — are accessible by expressway or first-class highway. Every township and eligible administrative village now has paved roads, bus services and postal coverage, with courier services nearly fully in place.

The region currently has 28 airports, the highest number of any region in China, with 665 routes in operation. Over half of the China-Europe freight trains pass through the region. In addition, 119 bilateral international road transport routes have been established, along with 37 international cargo air routes.