can be seen from huge date numbers on the western entrance of Obersendling station. U4 With only and 13 stations, the U4 is Munich's shortest U-Bahn line. This line has originally been planned as U9 and is the only line that operates regularly with 4-car sets rather than the full 6-car set. The exceptions are Fridays in the late afternoon and during the Oktoberfest. The line's colour is mint green. The U4 begins in the west in the Laim neighbourhood at Westendstraße station, which it shares with the U5 line. Both U4 and U5 are the only lines of a joint line "family", which only branch out on one end of the common line, as an originally planned western extension of the U4 was first put on hold and was subsequently cancelled altogether. From Westendstraße the U4 runs east to Heimeranplatz, which connects to S7 and S20 S-Bahn lines. The next two station, Schwanthalerhöhe (originally called Messegelände, the German for "exhibition grounds"; the name was changed when the exhibition centre relocated to Riem in 1998) and Theresienwiese, are gateways to the Oktoberfest, and are therefore highly loaded during this event. Between both aforementioned stations, there is a track that links to Implerstraße to provide a connection to the depot in Fröttmaning. Theresienwiese is one of only two U-Bahn station in Munich (besides Fröttmaning station which serves Allianz Arena) to have the command centre booth that is opened during the Oktoberfest for supervising the masses of passengers. The south exit of the station leads to the northern entrance of Oktoberfest. U4 trains arriving from the east often terminate at Theresienwiese rather than continue to Westendstraße even during peak hours due to low traffic volume east of Hauptbahnhof. After Theresienwiese the U4 reaches München Hauptbahnhof (Munich Central Station); passengers can transfer to U1/U2 lines as well as to all S-Bahn lines (except S20) here. The next station is Karlsplatz (Stachus) with shorter and easier connections to S-Bahn (S1 to S8). Karlsplatz is the deepest station in Munich's U-Bahn network ( below the surface). From this point on, the U4 runs north of the S-Bahn cross-city tunnel. After passing Odeonsplatz, where an interchange to U3/U6 trains is possible, and Lehel, the U4 crosses the River Isar in a tunnel, and reaches Max-Weber-Platz, the last station that is shared with the U5. Here, the U4 branches off to the north, while the U5 runs