Many bridges on Germany’s federal highways were constructed in the 1960s and 1970s. Structural monitoring data enables more accurate assessment of real loads and structural resistance of these existing structures. However, monitoring methods applied in practice are heterogeneous, with no guidelines for the design of measurement systems, data evaluation, or data integration in the condition assessment. In September 2025, static load tests were carried out at the openBridgeLAB – a 45-meter-long prestressed concrete bridge located in Bautzen, Germany – to test and compare monitoring concepts under real-world conditions using various sensors. This paper presents crack monitoring approaches utilizing conventional sensors, including consideration of sensor placement influence and data evaluation methods. The focus lies on identifying the decompression load, as well as crack propagation over the cross-section and crack width under varying loads in the coupling joint cross-section. The study evaluates existing monitoring methods and highlights potential improvements.