Sanya's 1st underwater tunnel to open for traffic in 2026

The Sanya River Estuary Passage is under construction. [Photo/Sanya Daily]

As a key project in Hainan province and Sanya's first underwater tunnel project, the Sanya River Estuary Passage has made rapid progress since construction began in September of last year.

It is expected that the project will enter its main construction phase next year and begin trial operation in 2026.

The project's total investment is 2.67 billion yuan ($366 million), with a designed tunnel length of about 3 kilometers. It spans the Sanya River estuary and connects Jianshe, Shengli, Sanya Bay, and Nanbianhai roads on both sides of the river. It includes a main line, three ramps, and eight entrances and exits.

Once completed, the project is expected to reduce the detour distance for residents and tourists by 5 km, and it is set to relieve traffic congestion on Sanya's key roadways.