The topic of the master's thesis is the presentation of the preliminary design of the Čilipi road interchange, which is located on the planned corridor of the Dubrovnik-Čilipi state road. Two variants of the interchange are presented in the master's thesis. The first variant is a two-level intersection in the form of a left trumpet, where the roads are connected by direct, semi-direct and indirect ramps. The intersection of the ramp with the D8 state road is designed as a roundabout with three legs. The second variant of the is also designed as a two levels interchange in the form of a diamond, where the roads are connected by direct ramps and two four-leg roundabouts are designed on both sides of the Dubrovnik - Čilipi state road, connecting the D8 state road and two direct ramps. Preliminary design shows horizontal and vertical alignment and cross-sections of all roads, interchanges and roundabouts elements. The Dubrovnik - Čilipi and D8 state roads were designed in accordance with the Regulation on the basic conditions that public roads outside built-up areas and their elements must meet from the point of view of road safety (Official Gazette 110/2001). All roundabouts were designed according to the Croatian guidelines for the design of roundabouts on state roads (Croatian Roads 2014), while the ramps were designed according to the German guidelines (RAL 2012). All roads, interchanges and roundabout elements were designed using the OpenRoads Designer and AutoCAD programmes.