Costs for a massive road infrastructure project in the Belgian city of Antwerp have spiralled out of control, now costing the European Union country almost £3 billion more than expected.

Construction commenced in 2017 and should be completed by 2033, so it will not be a surprise if more hidden costs reveal themselves in the nine years.

The Oosterweel Link project was first proposed in 1996, intended to complete the R1 Antwerp Ring Road. The route will provide an improved connection between the Expressweg (E34) through a tolled tunnel running underneath the Scheldt and a twin deck tunnel under the Albert Canal to the Antwerp Ring Road.

The mega-project is classed as one of Europe’s most vital projects.

The city of Antwerp is perfectly placed for international trade with the Netherlands to the north, Germany to the East, Brussels to the South and to the West the North Sea. It is also home to one of the globe’s most important seaports, with crucial highways linking other countries and cities with the Antwerp Ring Road.

The ring road in its current state has become notorious for congestion and traffic jams.

The 15km-long motorway connection is being developed by Lantis and consists of five sub-projects including Linkeroever, Zwijndrecht, Scheldt tunnel, Oosterweel junction, Canal tunnels and R1-Noord. The Scheldt Tunnel is where the left and right banks of the river will meet.

Jan Bauwens, project director for the consortium, said: “First of all we had to excavate a huge construction pit going up to 25m below the surface. That meant dewatering of the soil and excavating.

“From the moment we had this construction pit ready we could start building the actual tunnel. And that is what we are building at this moment,” reported The B1M earlier this year.

Bauwens also told the publication that workers would have to navigate “a lot of obstacles” and that’s “because it’s also the area where the old city walls were situated.”

The tunnels will allow drivers and cyclists to travel through Antwerp underground, with two-directional travel facilitated by stacking some of those sections on top of one another.

The project was originally expected to cost €6.8 billion (£5.7 billion) but the cost has now spiralled to €10.1 billion (£8.5 billion) due to a number of factors, according to World Highways.

These factors include increased costs for materials and labour since the COVID-19 pandemic as well as unforeseen technical challenges and the need for additional pollution measures.