On Sunday, plans to build the King Hamad Causeway that will be connecting Saudi Arabia to Bahrain were finally confirmed.

"The tender for the King Hamad Causeway will be launched after six months and is expected to start mid-2021. It should be completed in three years،" Saudi Arabia's ambassador to Bahrain, Abdullah Al-Sheikh، told Al Arabiya.

According to Arab News, the 25 km bridge, which might cost between $3-$4 billion dollars, will compile three lanes - one for a passenger train, another for a cargo train, and one for cars.

In a bid to avoid investing government funds, the causeway will follow the B.O.T (Build, operate, transfer) form of project financing. 

A private entity will be responsible for building the project and operating it until all money invested - plus profits - are returned. Subsequently, the ownership will then be transferred back to both Gulf nations.

According to the Saudi Ministry of Transportation, the project will be auctioned in the coming six months to make way for private companies to bid for a chance of financing and operating the causeway. A decision should be taken by mid-2019.

The bridge will form a strong economic link between Saudi Arabia and Bahrain, as well as boost the trade and economy of the UAE, Kuwait, and Oman.

In addition to the causeway, a 70 km railway will be built to connect "a passenger terminal in Salmabad and freight facilities at Khalifa bin Salman Port in Bahrain to the Saudi railway system," Reuters reported.

The new King Hamad Causeway will be the second water bridge to connect the two Gulf countries, following the 1986 King Fahd Causeway - which registered "19 million crossings in 2013" and "has been credited for growth in Bahrain's retail and industrial markets".

The project was first pitched in 2014 and approved after a meeting between the late Saudi King Abdullah and Bahraini King Hamad Al Khalifa.

Middle East Construction News previously reported an expected boost in Bahrain's residential market in case the second causeway is built. 

"We have recorded a steady rise in demand from Saudi nationals seeking to purchase weekend homes in Bahrain this year. The announcement of a second connection to Saudi will no doubt boost the performance of the residential and retail markets further," Harry Goodson-Wickes, head of Bahrain-based real estate consultancy Cluttons' said at the time.