The Fehmarnbelt fixed link in the Baltic Sea will connect the Danish island of Lolland with Germany's Fehmarn island and is expected to boost transportation between central Europe and Scandinavia. Spanning 17.6 km, it will be by far the world’s longest road and rail immersed tube tunnel (IMT), comprising of a four-lane motorway and a double-track railway. The Fehmarnbelt link will cut journeys across the sea from 45 minutes to about 10 by car and 7 by train.
The first major combined bridge and tunnel sea-crossing project in China is the Hong Kong-Zhuhai-Macau Bridge project. Consisting of three cable-stayed bridges and one 6-km sea crossing tunnel, it will have a total length of 55 km. It will be the world’s longest sea bridge and will link three cities in China's Pearl River Delta — creating one mega-city of 42 million people and slashing travel time between Hong Kong and Chinese city Zhuhai from three hours to just 30 minutes.
It was April 4, 2017, when the work of tunneling machine Bertha was complete, breaking through into her disassembly pit and marking the end of the 1.75-mile long State Route 99 (SR 99) tunnel beneath Seattle. Now, the Washington State Department of Transportation released a drone video that shows the ongoing construction work from end-to-end inside the tunnel.