This UNE report aims to serve as a guide for control operations in the maintenance of metal structures and civil works of vertical dynamic signalling that are part of the set of elements that make up the equipment of a road, in order to maintain the facilities in good condition from the actions to be carried out in each of the structures. The purpose of this report is to define and specify the inspections to be carried out, as well as to propose a format for the collection of information with which to report possible incidents to the competent body, not including in the scope of this report the possible corrective actions to commit. This report also proposes a periodicity of the inspections to be carried out, which is defined by contemplating a new structure. In the case of an existing structure for which there is no evidence that the inspections defined here have been carried out, it will be necessary to carry out a specific inspection that generates a "zero date" from which the inspections and frequencies indicated in this report. Some recommendations for this specific inspection are included in Annex B. Also included in Annex C, some acceptance and rejection criteria (tolerance) for some of the inspections indicated in this report.