Impact of wind bora on Croatian highways and bridges

This paper describes problems caused by wind along motorway section Sveti Rok Tunnel – Posedarje Interchange. Due to relief characteristics along this section (Velebit Mountain meets Adriatic coast) wind velocity and direction vary a lot. During the wintertime, northern to northeastern wind bora blows in this region (Figure 1) reaching enormous wind velocities. Studies have shown that the lateral wind speed exceeding 30 m/s is critical for vehicle's stability on a dry roadway. During stronger wind blows and severe roadway conditions, mentioned motorway section is closed for traffic.