in stages from 1974 onward and has adopted the term S-Bahn since 1995. It is also the only one in Switzerland to use a coloured "S" logo. In 1990, the Zürich S-Bahn, went into service. As of 2022, this network comprises 32 services, covering a large area in Switzerland (and parts of southern Germany). Further S-Bahn services were set up in the course of the Bahn 2000 initiative in Central Switzerland (a collaborative network of S-Bahn Luzern and Stadtbahn Zug), and Eastern Switzerland (S-Bahn St. Gallen). The Basel trinational S-Bahn services the Basel metropolitan area, thus providing cross-border transportation into both France and Germany. A tunnel connecting Basel's two large intercity stations (Basel Badischer Bahnhof and Basel SBB) is planned as Herzstück Regio-S-Bahn Basel (lit. heart-piece Regio-S-Bahn Basel). An international S-Bahn network also existsts across the Swiss-Italian border, in the Swiss Canton of Ticino and the Italian state of Lombardy. Services are operated by Treni Regionali Ticino Lombardia (TILO), a joint venture between Italian railway company Trenord and Swiss Federal Railways (SBB CFF FFS). The RER Vaud of Lausanne and the Léman Express of Geneva serve the area around Lake Geneva (fr. Lac Léman). The Léman express network expands across the Swiss-French border. It is the largest cross-country S-Bahn network of Europe. Léman express was launched in December 2019 and is operated by Swiss Federal Railways (SBB CFF FFS) and SNCF. Another transborder network for the Lake Constance (Bodensee) area, connecting up to four nations, is under discussion. This network would extend across the German states Baden-Württemberg and Bavaria, the Austrian state Vorarlberg, the Principality of Liechtenstein (S-Bahn FL.A.CH), and the Swiss cantons of Appenzell Ausserrhoden, Appenzell Innerrhoden, Schaffhausen, St. Gallen and Thurgau. Possible names are Bodensee-S-Bahn and Alpenrhein-Bahn. Presently, an hourly service, S3 of Vorarlberg S-Bahn (ÖBB), connects Bregenz (A) with St. Margrethen (CH), and a less frequent service (S2) operates between Feldkirch (A), Schaan (FL) and Buchs SG (CH). The S14 and S44 services of S-Bahn St. Gallen both connect Konstanz (D) with Kreuzlingen and Weinfelden (both CH), and since 2022, some S7 services continue from Rorschach (CH) to Bregenz and Lindau-Reutin (D). Additional transborder services are planned. The future of S-Bahn Liechtenstein is uncertain since a voter referendum in 2020. The Chur S-Bahn provides services around Chur, the capital of the alpine Canton of Graubünden (Grisons) in south-eastern Switzerland. The Aargau S-Bahn is a small network that