 Currently class 612 diesel multiple units operate hourly through the regional station on the Frankfurt Central Station–Saarbrücken Central Station route.A three-track underground station was already envisaged when a new and larger passenger terminal was planned at Frankfurt Airport in the mid-1960s.In April 1969, Deutsche Bundesbahn (today called Deutsche Bahn) and the airport operator FAG (today called Fraport) signed a funding agreement on connecting the airport to the rail network.