The Črni Kal Viaduct

 With its 1065-metre length, a surface of 28,173 square metres and a maximum pier height of 95 metres, the Črni Kal Viaduct is both Slovenia's longest motorway bridge and its tallest structure. The viaduct was built as a part of the new motorway linking Ljubljana, the capital, with the Slovenia costal region (Klanec – Srmin section) in the period between November 2001 and September 2004. The viaduct is the most demanding structure built on Slovenian motorways in terms of functional requirements, construction and technological capacity, design requirements, the difficult installation into the environment linked with the preservation of natural environment, as well as in terms of investment costs and easy maintenance. The viaduct consists of two separate carriageway superstructures that rest on joint Y-shaped piers. The shape of the piers is the main element of design that is a special distinctive feature of this Slovenia's largest viaduct, thus making it stand out among similar bridging structures abroad. In designing the project, road safety, protection from strong gusts of north-east wind and black ice were the main guidelines. A special 3–3.5-metre high wind barrier will protect drivers from strong gusts at this lofty height, while the road surface ice sensors will provide road condition information to road maintenance service in Kozina

Stamp Issue: 2004.09.15