There are about 65,000 bridge structures in the infrastructure network of the Federal Republic of Germany. Due to the long operating phase of bridges, they have an influence on sustainability. To evaluate the sustainability of bridges in the operational phase, digital building models can serve as a consistent and structured database to increase the efficiency and transparency. In this article, an innovative evaluation system for measuring and assessing the sustainability of a bridge structure in the operational phase based on a digital bridge twin is developed. First, the workflow is presented in a process model and the necessary requirements for the digital twin of the bridge structure are defined. In addition, the semi‐automatic sustainability assessment system is described and the linkage via an interoperable interface to the digital twin is designed. The approach is tested and validated using a real demonstrator. The result of the paper shows an approach to use digital twins for a novel and semi‐automatic sustainability assessment in the operation of bridge structures.