Developing design for obtaining the building permit with positive technical control report issued by technical control reviewer appointed by contracting authority, developing detailed design for the Works, developing as-built design in accordance with Serbian law and reconstruction and modernization of the existing track and construction of a second track on the railway section Stalac – Djunis, 17.1 km long to double track and speeds of 160km/h. Tunnel 4, L=3275m, is subject of a separate contract and is not included in this contract. The required Works will be carried out in accordance with FIDIC Conditions of contract for Plant and Design-Build for Electrical and Mechanical Works Designed by the Contractor (Yellow Book), First Edition 1999.