The Črni Kal viaduct
The Črni Kal viaduct is one of the most demanding bridging structures on the Slovenian motorways and the biggest viaduct in Slovenia.
The Črni Kal viaduct on the motorway section Klanec—Ankaran is a part of the Primorska leg of motorway A1. It consists of two separated pavement structures running on joint ray-shaped columns. It crosses the Osp valley in the horizontal radius of 800 m at the height from 10 to 95 m.
The Črni Kal viaduct is the most demanding bridging structure in Slovenia with regards to execution and design.