The study that will be presented, was carried out in a civil construction site of a double-track railway tunnel, in Italy, by two students of the engineer course of the University Politecnico of Milano. During the month of October 2022, the implementation of the B-BS protocol officially started, with the objective to increase the adoption of safe behaviors and develop a safety-based value culture for the entire construction site. Later, in May 2022, because of the relevant problems, in terms of safety and productivity, of failures and breakdowns with the machineries, an extension of the BBS project was decided to be taken forward, that specifically focused on the change of behaviors related to the maintenance of the machineries used by the workers, specifically for the miners group. For this purpose, specific pinpointing on maintenance behaviors was taken forward, with the construction of a checklist that was then used to observe and measure the behaviors. Through the baseline phase the company’s management team had the possibility to conduct a detailed analysis of the status of the maintenance of the machineries and select the objective behaviors for improvement. Through the use of graphs and data, the paper will present how a BBS process, with observations, measurements of behaviors through checklist and release of immediate feedback and monthly safety meeting, had an effect on the objective of increasing the maintenance behaviors of the machineries was shown.