This study employs acceleration and strain-based finite element model updating (FEMU) techniques on a half-century-old multi-span concrete highway viaduct. While most FEMU studies on bridges rely only on acceleration data due to lower costs and ease of implementation, this research incorporates strain measurements taken at mid-span under truck passages, in addition to frequencies and mode shapes from acceleration data. The analyses were conducted separately for acceleration data (natural frequencies and mode shapes), strain data and a combination of acceleration and strain data. Three variables representing Young's modulus adjustment factors for different structural elements were updated. The intuitive error-domain model falsification (EDMF) proved itself over traditional FEMU techniques, such as residual minimisation, as it allows the incorporation of acceleration and strain data without the need to specify the weights for each of them. Furthermore, once an additional source of data (strains) is added, the information gained becomes clearly visible, and the results of the FEMU are more sensible from an engineering perspective. This confirms the necessity of having data from various sources for a quality FEMU. The results showed an overestimation of the internal main girders' design stiffness, ranging from 25-50%.

viaduct; bridge; finite element model updating (FEMU); error-domain model falsification (EDMF); structural health monitoring (SHM)