Masonry arch bridges are still a common type of existing railroad bridges and have often been in service for more than 100 years, making them significant in the context of railroad history, but also as an essential part of today's infrastructure in Germany. Although most of these structures still have a sufficient load-bearing capacity, they are often replaced by reinforced concrete frames due to visible damage. One reason therefore is a lack of knowledge about the load-bearing behavior, which means that it is often not realistically represented in current recalculations. With the conservation and continued use of arch bridges building culture can be preserved, costs reduced and in addition a contribution made to climate protection. For this purpose, a series of load tests are carried out on different arch bridges in the network of Deutsche Bahn, applying defined static and dynamic loads and measuring the behavior of the structure. Two concepts are used to measure deformations of the arch as well as the subsequent soil. The results are used to calibrate finite element models. On the one hand, parameter studies can be carried out on the influences on the load-bearing behavior of arch bridges and, on the other hand, simplified, realistic design models can be derived. The paper discusses the concept of the load tests and presents results.