The Ministry of Transport has developed the decision support model MRoad for rapid design of pavements embankments. MRoad predicts costs, construction time, effect on adjacent structures and roads and maintenance. This publication describes the interaction of the model with other tools used in motorway design. The relationship between functional requirements and requirements for geotechnical design is explained. The design process is illustrated by a case study for widening a motorway on soft soil. Considering costs and road capacity during construction, a piled embankment is the best choice. The presence of soft soil has a large effect on project costs.