In this thesis, research is performed into parametric design of balanced cantilever bridges within the total road design. The main research question is: What can be achieved by using a parametric model in the preliminary design phase, with the possibility to optimize and compare concrete bridges on material usage, costs and environmental impact? And to answer this question, the cantilever bridge and all other elements in the road design are investigated and a parametric model is developed. In this model the total vertical alignment of the road design is implemented along with approach bridges, substructure and foundations. Furthermore, the results of the designs are visualized in a 3D environment compared with an overview of the material costs and environmental impact. In the "Discussion", the following is concluded: Although the parametric model for the preliminary design of concrete cantilever bridges took a long time to develop, this time investment can be regained by using the model several times. Because by using the parametric model for the preliminary design of concrete bridges, the design time per procurement is decreased significantly. Furthermore, the design process of the balanced cantilever bridge has become more flexible since changes are automatically implemented for the whole model. Also the chance for (human) errors is decreased, for instance the risk of data loss is minimized due to the model’s single environment. Since only a limited amount of calculations is performed by the model, the results of the analysis must be used with caution. Another advantage is the instant results as produced by the model. These results consist of a visualization of the design and an overview of the material amounts, with their costs and environmental impact. Furthermore, the model is also able to optimize these results in a fast way due to a smart evolutionary solver. This all together makes the parametric model a useful tool with high potential, but it should be further developed and improved.