The tunnel was originally designed to be 325 metres (1,066 ft) long, but it was shortened due to the landslide on the western portal in the zone of contact between Paleozoic and carbonate layers.

[1] The tunnel is noteworthy since it comprises a 58-metre (190 ft) bridge spanning a cavern found during excavation.

The surrounding rock was stabilized using geotechnical anchors to ensure safety before the bridge construction started.

This was achieved by construction of a concrete structure covering the bridge deck, hiding the cavern from the motorway users and giving them impression of driving through an unbroken tunnel tube.

[2] Traffic is regularly counted and reported by Autocesta Rijeka–Zagreb, operator of the A6 motorway and the tunnel, and published by Hrvatske ceste.