second section of the Limmattalbahn opened in December 2022. The Limmattalbahn is a light rail service (route 20) from Altstetten railway station to Killwangen-Spreitenbach railway station. It is operated by Aargau Verkehr AG (AVA). The extension of route 2, together with a delay to the delivery of the Bombardier Flexity trams on order (see Future developments), required a reorganisation of other routes in order to free up trams for route 2. In addition two Mirage trams, withdrawn from service nearly ten years earlier but held in reserve, were reinstated to cover some peak workings. The first of the new Flexity trams arrived in Zürich on 13 November 2019, but it is not expected to enter passenger service until the summer of 2020. The next extension of the urban route network, from Radiostudio to Holzerhurd (called Tram Affoltern), is currently planned and expected to open in 2029. Tram route 11 will operate on this section to Zürich Affoltern and replace the trolleybus route 32 on that section (route 32 will terminate at Bucheggplatz). At the same time, tram route 15 will be extended from Bucheggplatz to Auzelg on the tracks currently used by route 11. Also under discussion is the so-called Tram Nordtangente, a tram line from Zürich Affoltern to Schwamendingen via Oerlikon. Other extensions (after 2035) are under discussion, including the reenactment of tram route 1 from Hauptbahnhof to Altstetten (served by trolleybus route 31 since the original route 1 was terminated and its tracks removed in the 1950s). History preserved The Zürich Tram Museum, located at the former tram depot at Burgwies (on tram route 11), preserves many examples of Zürich's former tramcar fleet, along with other related exhibits. Operation Route network The following tram lines make up the urban routes and the routes of the Glattalbahn and Limmattalbahn networks. Portions of routes in italics are on the Glattalbahn (lines 10, 11, 12) or the Limmattalbahn (lines 2, 20) tracks (otherwise VBZ tracks) Brackets indicate portions of a route that are only served by that line during peak hour. Deviations from regular routes are possible (e.g. during events such as Street Parade) The abbreviation Bhf. (Bahnhof) indicates stops next to railway stations Hauptbahnhof (HB) is Zurich main station, with four nearby tram stops: Bahnhofplatz/HB, Bahnhofquai/HB, Bahnhofstrasse/HB and Sihlquai/HB. Two other stations, Sihlpost/HB and Central, are within walking distance All journeys on routes 6, 10 and 12 are operated by