and construction of a new four-track station underneath the Südring, serving the U3, U9, and U29, and connecting to the new aboveground station serving regional trains and possibly the S-Bahn if the future S-Bahn-Ring is approved. The new U-Bahn station would be called Impler-/Poccistraße to differentiate it from the current U3/U6 – Implerstraße and Poccistraße stations. The current Poccistraße station has serious structural problems requiring expensive maintenance and extensive monitoring; it is cheaper to build a new station nearby than to continue using Poccistraße. At Hauptbahnhof, the new dedicated U9 platform would be built underneath the current S-Bahn platform but above the U4/U5 platform. The platform would be located underneath the regional and long-distance train tracks between Holzkirchner Bahnhof (Holzkirchner wing station, serving southeastern Bavaria) and Starnberger Bahnhof (Starnberg wing station, serving southwestern Bavaria) with a new mezzanine level connecting the U9 platform with both wing stations and the rest of Hauptbahnhof. The advantage of locating the U9 platform in the western section of Hauptbahnhof is a quick transfer between platforms without a long, circuitous walk from one platform to other via the grand platform in the east. On 3 July 2019, Deutsche Bahn announced the new "2. Stammstrecke — Die Optimierungen" (Second Trunk Line Optimisation). The State of Bavaria and the Munich city council want the first U9 station to be built at the Hauptbahnhof at the same time as the reconstruction of the Hauptbahnhof main building and the construction of the second S-Bahn trunk line. The design revision relocates the U9 platforms from the west end of the regional and long-distance platforms to the middle of the main Hauptbahnhof building below ground. The relocation places the U9 station directly above the second trunk line station in a cross arrangement. This improves the passenger flow between two current U-Bahn lines (U4/U5 and U1/U2/U7/U8), one current S-Bahn trunk line, and the above-ground level. U26 tangent line Another proposal for crosstown travel in the north between U2 - Am Hart and U6 (or U9 when opened) - Kieferngarten is under consideration. This U26 would serve the people who live in the north and don't need to travel south in order to travel between northwest and northeast regions. The high cost and fewer stops as compared to tram line would make this proposal less feasible. However, the new massive expansion plan for BMW's Forschungszentrum (Research Centre) in the north of BMW headquarter