In Budapest, after five and a half years of hardships, from May 2023 passengers can finally use the M3 metro, one of the country’s busiest, on a full line again. The renovation of the metro was timely for both safety and aesthetic reasons. Groundwater infiltration in the tunnels caused track defects, which also caused the metro trains to deteriorate severely. Maintenance of the technical infrastructure became increasingly difficult as equipment became obsolete. In addition to...












