The master thesis presents five variants of the preliminary design of the A1 Zagreb - Split - Dubrovnik motorway in the area of Dubrovnik-Neretva County between Osojnik and Zarovac. All variants are designed in accordance with the valid regulation (Official Gazette 110/01) and the spatial plan of Dubrovnik-Neretva County. The variants are designed for a design speed of 110 km/h and 130 km/h. The length of the sections is between 4,080,712 m and 4,160,994 m. The horizontal alignment consists of 2 straight lines and 4 or 5 curves. The curve radii are between 1,200 and 2,000 m. The vertical alignment consists of straight lines and crest curves. The maximum longitudinal gradient is 4%, the minimum 0.5%. The cross-section of the road consists of two carriageways separated by a median, each with two lanes. In three variants, the lane width is 3.75 m with a 2.5 m wide stopping lane. Two variants were designed with a lane width of 3.5 m. Stopping sight distance was tested in both directions for the selected variants. The test results showed that the sight distance conditions were not met in a certain part of the section and the side slope had to be widened. As part of the design of the corridor of the new road, the reconstruction of the existing county road Ž6235 and the construction of an overpass are planned.