Finland’s planned 8km Hailuoto Causeway is likely to cost around €74 million, according to the North Ostrobothnia Centre for Economic Development, Transport and the Environment.
The causeway will connect the small town of Huikku on Hailuoto Island in the Gulf of Bothnia with Oulunsalo on the mainland, around 540km north of Helsinki.
The causeway will include two bridges, 740m and 770m in length, as well as an artificial island.
Finland’s Ministry of Transport announced last September that work on the Hailuoto Bridge would be done under a public-private partnership. Work is to start sometime this year, Anne Berner, transport minister, said at the time.
A ferry operates regularly between Hailuoto and Oulunsalo during summer. In winter the northern end of the gulf usually freezes, but this allows for a 7km ice road – Finland’s longest - between the two towns.
In order to support traffic, the ice must be 40cm thick. However, Finnish media have reported that the sea-ice off the coast of Oulu has been taking longer than in years past to freeze sufficiently enough for the road, part of route 816, to take vehicles.
Clearing the snow off the ice speeds up the freezing process, according to the local road contractor Touhu-palvelut which is also in charge of maintaining the ice road. The road also has to be smoothed out before vehicles can use the predetermined path designated as a safe crossing.
In 2008, instead of remaining open until March, the route lasted only around ten days before it became unsafe. In 2015 the ice road never materialised at all – an extremely rare occasion, noted the contractor in 2016.