The Outer Ring tunnel, also known as the Taihe Road Tunnel, is a

highway A highway is any public or private road or other public way on land. It includes not just major roads, but also other public roads and rights of way. In the United States, it is also used as an equivalent term to controlled-access highway, or ...

tunnel A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...

under the

Huangpu River The Huangpu (), formerly romanized as Whangpoo, is a river flowing north through Shanghai. The Bund and Lujiazui are located along the Huangpu River. The Huangpu is the biggest river in central Shanghai, with the Suzhou Creek being its ...

Shanghai Shanghai, Shanghainese: , Standard Chinese pronunciation: is a direct-administered municipality and the most populous urban area in China. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the ...

. The tunnel serves as part of the S20 Expressway and was completed on June 21, 2023. The tunnel runs east to west from Baoshan District to Sancha Port after crossing the Huangpu. The tunnel is long and features 8 lanes with a speed limit of 80 km/h, which made it the longest underwater tunnel in Asia and third worldwide by length. The tunnel has been closed for 12 months due to construction since March 22, 2024.

References

Tunnels completed in 2003 Road tunnels in China 2003 establishments in Shanghai {{Shanghai-stub