(CNN) – After nearly four years of construction, China’s longest underwater road tunnel is now open to traffic.
At 10.79 kilometers (6.65 miles), the Taihu Tunnel stretches under Taihu Lake in east China’s Jiangsu Province, about 50 kilometers east of Shanghai.
According to Jiangsu government officials, the tunnel was built at a cost of 9.9 billion yuan (about $ 1.56 billion). Construction began on January 9, 2018.
More than 2 million cubic meters of concrete were used to build the two-way tunnel, which has six lanes and is 17.45 meters wide, reports the official Chinese news agency Xinhua.
The tunnel ceiling has been fitted with colored LED lights, designed to prevent driver fatigue.
A view of the LED ceiling installed in the 10.79 kilometer tunnel under Taihu Lake.
FeatureChina / AP
The tunnel is part of the 43.9-kilometer Changzhou-Wuxi Expressway, which opened to the public on December 30, 2021. It provides an alternative highway for travelers traveling between Shanghai and Nanjing, the capital of Jiangsu.
Connecting the highways of Suzhou, Wuxi and Changzhou, it was built to alleviate the traffic pressure on the towns beside Taihu Lake while promoting the economic development of towns in the Yangtze River Delta region.
The Tokyo Bay Aqua-Line underwater tunnel portion, a vehicle highway that passes under Tokyo Bay, is 9.6 kilometers long.
Top image: Aerial photo taken on September 5, 2021 of the Nanquan section of the newly opened Taihu Tunnel in east China’s Jiangsu Province. Credit: Li Bo / Xinhua via Getty Images