The longest tunnel in Croatia to be built as major rail project moves forward

Sveti Rok Tunnel (Photo credit: Andrej Neuherz/CC BY 3.0)

ZAGREB, 14 July 2026 – Croatia’s ambitious new Zagreb–Rijeka lowland railway has taken another step forward, with plans for the country’s longest tunnel forming one of the project’s most significant features.

HŽ Infrastruktura has opened bids in a public procurement process for technical assistance covering the procurement and implementation of the Alliance contract for the design and construction of the Karlovac–Skradnik and Skradnik–Krasica–Tijani sections of the future railway.

Two bids were submitted. Finland’s Vision Oy offered €1.02 million, excluding VAT, while a Croatian consortium led by KPMG Croatia, together with Projekt jednak razvoj and the law firm Kallay & Partners, submitted a bid of €692,500, excluding VAT. The bids will now be evaluated before a contractor is selected, Večernji list writes.

According to HŽ Infrastruktura, the Alliance contract is a modern procurement model used for large and complex infrastructure projects. It is based on partnership between the client and contractor, with the aim of speeding up both procurement and construction.

The new lowland railway is part of three major Trans-European Transport Network (TEN-T) corridors, the Mediterranean Corridor, the Baltic Sea–Adriatic Corridor and the Western Balkans–Eastern Mediterranean Corridor, linking the Port of Rijeka with Hungary and other Central European countries.

Once completed, the railway between Zagreb and Rijeka will be approximately 175 kilometres long, reducing the route by around 56 kilometres compared with the existing line.

The planned double-track, electrified railway will allow passenger trains to travel at speeds of up to 160 km/h and freight trains at up to 120 km/h. The project also includes the construction of five new railway stations and one additional stop.

Among the planned infrastructure will be more than 30 tunnels and viaducts, including what is set to become Croatia’s longest tunnel.

The 14-kilometre tunnel will pass beneath the Velika Kapela mountain range. For comparison, Croatia’s two longest road tunnels, Sveti Rok and Mala Kapela, have a combined length of around 12 kilometres.

HŽ Infrastruktura says the new railway is essential for maximising the potential of the recently developed Rijeka Gateway terminal by enabling a greater share of freight arriving at the Port of Rijeka to be transported by rail towards Hungary and Central Europe.

The company adds that the new line will significantly increase railway capacity and safety while allowing freight trains up to 750 metres in length to operate. It also says the project will support the continued development of the Port of Rijeka and could facilitate future expansion towards Omišalj on the island of Krk, strengthening Rijeka’s position among the leading ports in the northern Adriatic.