According to plans the implementation of the Sharq crossing project starts second half of 2020 and includes subsea tunnels. It is expected to cost $12 billion.

Originally proposed in 2013, it was taken off the priority list until 2020.

The project comprises of the following 2 Immersed tunnels with a total length of approx. 6 km and 3 cut-and-cover tunnels in addition to other things e.g. bridges, roads etc.

https://www.iloveqatar.net/news/general/top-5-mega-projects-underway-qatar