Učka Tunnel: How Istria is Connected by Road to the Rest of Croatia

More than 15,000 people gathered on Sunday September 27, 1981, for the opening of the Učka Tunnel, one of the largest traffic projects in Croatia at the time. The 5062-meter-long tunnel was not only a construction feat but also a symbol of traffic connectivity between Istria and the rest of Croatia.

Meeting in the belly of Učka

The entire demanding project was accompanied by a great deal of skepticism. At one point, it was even suggested to abandon the breakthrough of Učka and connect Istria via the so-called island connection, that is, bridges over Krk and Cres.

Construction began in August 1976, with workers from Split’s Konstruktora, who were tunneling from the Kvarner side, and Zagreb’s Hidroelektra, which was advancing from Istria. They greeted each other for the first time when the last mine was activated on May 5, 1978 – at 4:15 AM, it made a hole through which ‘the light at the end of the tunnel’ could finally be seen. The deviation between the two teams tunneling from opposite sides was only five centimeters, which is still considered an extraordinary engineering achievement today.

Traffic connection of Istria with the motherland

The tunnel was opened as part of the celebration of the 38th anniversary of the decision to unite Istria with the motherland, which gives the event an additional symbolic dimension. The tunnel not only shortened the journey between Kvarner and Istria but also enabled a fast, safe, and year-round road connection across the mountain massif that had represented a natural barrier for centuries.

Although Istria is geographically part of Croatian territory, it had long been isolated in terms of traffic. Učka and Ćićarija had hindered connections with the Rijeka and Zagreb areas for centuries. Traveling over the pass was slow, especially in winter, and the development of tourism and the economy constantly faced limitations of the then traffic network.

For this reason, the opening of the tunnel in 1981 was perceived as the beginning of a new era. Istria finally received a fast, safe, and year-round modern road connection with the rest of the country, which was particularly significant for the population, the economy, and the increasingly strong tourism.

The second tube and the end of the traffic bottleneck

Since the end of 1995, the tunnel has been managed by the concessionaire, the Franco-Croatian company BINA-Istra, led by the French group Bouygues, which built the first phase of the Istrian Ypsilon in semi-profile by 2006.

More than four decades after its opening, traffic through Učka has increased multiple times. At the peak of the tourist season, more than 20,000 vehicles daily pass through the tunnel, which has become one of the largest traffic bottlenecks in Croatia.

In 2024, the second tube of the Učka Tunnel was opened, and during 2025, the renovation of the original tube was completed. This allowed for the first time a full profile through the mountain, significantly greater traffic safety, and a higher capacity for connecting Istria with the rest of Croatia. However, the project is not yet complete.

By highway from Zagreb to Istria

Currently, the last section of the full profile is being built between Matulji and the Učka Tunnel. Only at the beginning of 2027, nearly half a century after the opening of the Učka Tunnel, will Istria be connected by a full-profile highway to Zagreb and the rest of Croatia for the first time.

In other words, the process that began with the opening of the first tunnel tube in 1981 will now finally be completed.

From the first attempts to the study in 2026

The idea of tunneling Učka for railways is significantly older than the road tunnel and dates back to the 19th century. After World War II, it was revived, and in 1951, construction of the tunnel from the direction of Poljana even began, but the work was soon halted. President Franjo Tuđman opened preparatory works for a new, 14.37-kilometer-long Ćićarija tunnel in 1993, but that project also did not come to fruition. It was revived in 2008 as part of major plans to build a lowland railway line to Rijeka.

Finally, in May 2026, a concrete step was taken – a study for a railway connection with the Croatian railway network was contracted. The central object of the future route would be approximately a 15-kilometer-long Ćićarija railway tunnel.

More than a tunnel

When the Učka Tunnel was opened on September 27, 1981, Istria broke through its greatest natural traffic barrier. Forty-five years later, both tunnel tubes have been opened, the highway connection to Zagreb is being completed, and discussions about a railway tunnel through the mountain are being revived.

Few infrastructure projects so clearly illustrate Croatian traffic history: from a peninsula that was partially isolated for decades to a region that could soon have a full highway connection and one day a modern railway connection with the rest of the country.