The tram network serves most city neighbourhoods, and is the backbone of public transport within the city, albeit supplemented by the inner sections of the Zurich S-Bahn, along with urban trolleybus and bus lines, as well as two funicular railways, one rack railway and passenger boat lines on the river and on the lake.

Recent expansions have taken the network into the suburbs beyond the city boundary, covering areas it retreated from in the first part of the 20th century.

The StStZ had also built many tram extensions, resulting in a dense network of tramlines serving most city neighbourhoods.

Despite Switzerland's neutrality, the economic effects of the Second World War slowed down the program, but by 1953 the VBZ, as the StStZ had become in 1950, had taken delivery of 177 such trams.

The recently delivered Swiss Standard trams were not seen as suitable for this, because they had doors on their tapered car ends that would not have aligned with the proposed underground station platforms.

The first design, known as the P16 or Karpfen, could not run on some existing routes, and only one batch of 15 motor tram and trailer pairs was built.

However this would have been at the expense of a coarser grained network, with much longer distances between U-Bahn stations than between the tram stops they replaced.

One section of the putative U-Bahn has since been adapted, as described below, for use by trams, whilst another now forms the terminus of the Uetliberg and Sihltal railway lines under the Hauptbahnhof.

Several sub-classes of the Tram 2000 were purchased, including articulated and non-articulated variants, and some without drivers cabs that could only operate in multiple with other cars.

[5][7] From the 1980s onwards, the system was increasingly acclaimed for its success in maintaining a high share of the modal split, and the Zurich model of transport provision was named after it.

Beyond the tramway, the Zurich S-Bahn rail network was introduced to serve the region beyond the city boundaries, taking on some of the role that was originally planned for the U-Bahn.

In 1990, the city's urban and regional transport were integrated by the introduction of the ZVV and its zone-based common fare structure.

Whilst the airport is served by the city's S-Bahn rail network, the economic growth and resulting congestion led to a need for a finer-grained form of public transport.

The responsible transport authority (the Verkehrsbetriebe Glattal or VBG) responded by constructing a new light rail system, the Glattalbahn.

[14][15][16] Tram Zürich West, an extension from Escher-Wyss-Platz to Bahnhof Altstetten Nord, in the city of Zurich, opened in December 2011.

[18][19] An extension of the tracks from Hardbrücke to Bucheggplatz and Milchbuck (project Rosengartentram und Rosengartentunnel), along with the opening of two new tram lines, was rejected by a referendum in 2020, however.

In addition two Mirage trams, withdrawn from service nearly ten years earlier but held in reserve, were reinstated to cover some peak workings.

[22][23] The next extension of the urban route network, from Radiostudio to Holzerhurd (called Tram Affoltern), is currently planned and expected to open in 2029.

The tracks are electrified using overhead line at 600 V DC, utilising a supply system shared with the city's trolleybus network.

By contrast, on VBG infrastructure in the Stadtbahn Glattal, VBZ trams operate on long stretches of dedicated track.

[12] Zurich's tram fleet is kept in the five operational depots of Hard, Irchel, Kalkbreite, Oerlikon and Wollishofen, together with a permanent way yard at Hardturm.

Burgweis depot now houses the Zurich Tram Museum's main collection, whilst Wartau is used as a workshop by that organisation.

Instead, tickets are randomly checked by roving teams of fare inspectors, and fines are imposed on passengers found without one.

[42] Tram services are operated within the fare and ticketing system provided by the cantonal public transport authority, the Zürcher Verkehrsverbund (ZVV).

Free transfer is permitted between different vehicles, lines, modes and operators, provided a ticket valid for the whole journey is held.

[43][44] Besides its passenger transport activities, VBZ, jointly with the city refuse and recycling department ERZ, operates the cargo tram to collect bulky waste.

The collected refuse is taken to a specially constructed siding at the ERZ yard adjacent to the Werdhölzli tram terminus.

[49][50][51][52] In May 2016, it was announced that VBZ had awarded a contract worth 358 million Swiss Francs to Bombardier Transportation for the supply of 70 7-section Flexity 2 trams, with an option for a further 70, to be delivered between 2018 and 2023.

After both Stadler and Siemens decided not to appeal this decision to the Federal Supreme Court of Switzerland, the contract was finally signed on 2 March 2017.

The Limmattalbahn, designated route 20, is a regional light rail service between Bahnhof Altstetten and Killwangen-Spreitenbach railway station.