Continuous monitoring of the dynamic properties of existing structures plays a relevant role in safety assessment and to support timely structural maintenance. However, the low amplitude vibrations in operational conditions often make reliable modal parameter monitoring very challenging. This paper presents some preliminary results of extensive investigations aimed at exploiting the capabilities of power spectral density transmissibility (PSDT) for automated operational modal analysis (OMA) in the context of civil SHM applications. The investigated aspects mainly concern the modal identification reliability, evaluated also through a comparative performance assessment of PSDT-based OMA with other well-established OMA procedures, and the automation of the dynamic identification process by using PSDT functions. Application of the proposed PSDT-based automated OMA procedure to simulated as well as experimental provided encouraging results.