Rijeka Tunnel Targets Adriatic Freight

Rijeka has the sea in its favour. What it lacks is the railway behind it.

Croatia wants its main port to do what Koper and Trieste already do well: pull cargo off ships in the northern Adriatic and send it quickly into Central Europe. The weak point is not the quay. It is the mountain railway rising inland from the coast. HŽ Infrastruktura, Croatia's state rail manager, has received two offers for technical advisers on a planned "lowland" Zagreb-Rijeka railway: a double-track, electrified line that would shorten the existing route by about 56 km and send a 14 km tunnel through the Velika Kapela range (Index, Croatia Week).

This is still the machinery before the machinery. Croatia is not yet awarding a construction contract. It is hiring advisers to shape the procurement, the stage where a project moves from political ambition into the harder world of specifications, risk and money.

Why 56 Km Changes the Freight Maths

A container ship can choose Rijeka, Koper or Trieste. The real contest begins once the box is lifted off the vessel. If the railway inland is single-track, steep and slow, the port's position on the Adriatic map loses much of its value. Shippers care less about coastal geography than about whether a container reaches Budapest, Vienna or Prague cheaply and on time.

The existing Zagreb-Rijeka line carries exactly the penalties Croatia is trying to escape. The proposed lowland route would allow 740-750 metre trains to run on gentler gradients and on double track (TEN-T Regulation (EU) 2024/1679). Train length matters because every extra wagon spreads the cost of a driver, locomotive and timetable slot across more containers. Double track matters because trains can move in both directions at once, creating far more usable paths in a day.

That is the commercial logic: heavier trains, lower traction costs and schedules that shippers can trust. It is also the Brussels logic. TEN-T, the EU's core transport network, prioritises schemes that remove bottlenecks on cross-border corridors. The Connecting Europe Facility, the EU fund for transport infrastructure, is designed to finance precisely this kind of link (CEF Transport). Croatia's strongest case is not that Rijeka needs a better railway. It is that Central European freight needs another functioning route to the sea.

The Rivals Have Their Own Problems

Rijeka is not chasing static competitors. Koper and Trieste know the same lesson: a port is only as strong as its inland rail.

Koper, Slovenia's only port, is spending more than €230 million to expand container capacity from about 950,000 TEU to 1.3 million TEU. A TEU is one 20-foot container, the standard unit used to count container traffic (Regional Obala). Its vulnerability is the long-delayed Divača-Koper second track, with Slovenian reporting alleging that rail projects are being overpaid by at least 30% (Info360).

Trieste has a different advantage: customs positioning and a long habit of looking inland. Italy's transport minister Matteo Salvini has promoted a Trieste-Belgrade railway to extend the port's reach into the Balkans (Trieste All News). But the recent closure of the Tarvisio rail crossing disrupted about 150 trains a week, a reminder that one weak point can quickly separate a port from its customers (ilnordest.it).

The landlocked countries between the Adriatic and the Danube are not sentimental about ports. They want leverage. ÖBB Rail Cargo Group has expanded its terminal at Přerov in Czechia and plans rail links to both Koper and Rijeka (ÖBB/RCG). Hungary treats Adriatic access as a strategic logistics question covering both energy and container cargo (G7/Telex). Their loyalty will go to the corridor that works.

Who Pays, Who Gains, What's Unproven

If Croatia gets this right, the first winners are port operators and freight companies. Inland logistics hubs in Zagreb and across Central Europe gain next. Importers and exporters gain more route choice and, possibly, lower costs.

The risk sits with taxpayers, Croatian and European. EU corridor funding committed on generous traffic assumptions is money that cannot be spent elsewhere. No verified cost-benefit analysis, construction timetable or traffic forecast has yet surfaced publicly. A Croatian maritime analysis describes Rijeka as the port with the greatest growth potential, provided it fixes its inland rail connection (Pomorac.hr).

Croatia has advanced the paperwork for a project that makes economic sense. But Rijeka will not win because it looks well placed on a map. It will win only if the new railway lowers the cost and uncertainty of moving cargo inland, and only if shippers choose those trains over the alternatives from Koper and Trieste. Until longer, heavier and more reliable trains are actually running into Central Europe, Rijeka has entered the race rather than changed its result.