Drive-by monitoring, also known as indirect monitoring or mobile sensing, offers clear advantages over other approaches to Structural Health Monitoring. This method capitalizes on the relationship between the vertical vibrations of a bridge and those induced by passing vehicles. By utilizing the vehicle as both the source and receiver of vibrations, valuable insights into the structural condition of the bridge can be obtained. While a variety of methods have been proposed in the literature, the majority of research has focused on highway bridges, leaving limited information on the applicability of indirect methods for monitoring railway bridges. This study aims to fill this gap by thoroughly examining the feasibility of drive-by monitoring for railway bridges, considering both theoretical and practical aspects. Real case studies from the Moroccan railway network will be presented to illustrate the discussed concepts.