The maintenance management of a railway metro network requires the programming of periodical monitoring campaigns on the tracks using several diagnostic technologies. Many of these technologies can be applied to measurement systems, installed on small trolleys/motorised railway vehicles/passenger operating trains, that are able to produce objective reports to describe the unequivocal status of anomalies in the tracks.
This study aims to investigate how the specific activity of the ultrasonic testing of the rail track (as a specific case of all diagnostic monitoring activities) is performed by the different metro companies, with regard to the technological (quality of the measurement instruments, quality of the software used for the analysis, etc…), organisational (frequency of the check, availability of expert certified operators and diagnostic coordinators, activity performed with internal resources or by a third-party company) and legal aspects.
The responses received as part of this study help to define trends and are presented in the final section, which also provides an overview of the widely-used procedures, certification methods, and tools. Recommendations based on the collected responses are also provided.