The tunnel project could be economically feasible using a public-private partnership (PPP) model in which the private sector finances the building of the tunnel and an EU grant would be needed to cover 40 percent of the costs, it can be seen from the results of the study.

After becoming operational, ticket revenues from the trains and tunnel fees would cover the tunnel's annual operational and maintenance costs. In addition, train operation would require subsidies. The subsidy from Finland and Estonia would be €280 million per year for 40 years.

Results of the study show that the region's direct profits from the tunnel, consisting primarily of time saved converted into money, would total more than €5 billion; indirect effects would bring in an additional €7 billion to the region.

The projected cost of the project includes, for instance, tunnel construction, two artificial islands, planning costs, stations, terminals and depots, but does not include the costs for rolling stock.

According to the FinEst Link feasibility study, the railway tunnel would help create in the future a metropolitan twin city region of three million inhabitants where people, goods and services could move around easily. The expanding labor market would create economic growth, open new possibilities for businesses and improve quality of life. With a travel time of just 30 minutes, the Tallinn-Helsinki tunnel would enable daily commuting across the Gulf of Finland as well as connect the rail network from Central Europe via Finland to the Arctic.

"From the viewpoint of deeper twin city integration and regional development, there could be major benefits from the tunnel," said FinEst Link project director Kari Ruohonen. "Geographically, Finland resembles an island, and the tunnel would offer a connection to the Central European rail network."

FinEst Link is an EU-funded research project focusing on studying the feasibility of an undersea railway tunnel connecting the Estonian and Finnish capitals of Tallinn and Helsinki. The total budget of the project is €1.3 million, co-financed from the Interreg Central Baltic program.

The project is led by the Helsinki-Uusimaa Regional Council in partnership with the cities of Helsinki and Tallinn, Harju County Government, the Finnish Transport Agency and the Estonian Ministry of Economic Affairs and Communications.