The Zürich S-Bahn () system is a network of rail lines that has been incrementally expanded to cover the ZVV area, which comprises the entire canton of Zürich and portions of neighbouring cantons (Aargau, Glarus, Schaffhausen, Schwyz, St. Gallen, Thurgau and Zug), with a few lines extending into or crossing the territory of southern Germany. The network is one of many commuter rail operations in German speaking countries to be described as an S-Bahn. The entire ZVV S-Bahn network went into operation in May 1990, although many of the lines were already in operation. Unusual among rapid transit services, the Zürich S-Bahn provides first class commuter travel; about a quarter of seats on each train are first class. History Before the construction of the Zürich S-Bahn, most trains to Zürich terminated at Zürich Hauptbahnhof (literally Zürich Main Station), apart from the Sihltal Zürich Uetliberg Bahn lines which terminated at Zürich Selnau. Originally built as a west-facing terminus, the Hauptbahnhof acted as a terminus for trains coming from all directions. It was connected to lines to the north and northeast via the Wipkingen Tunnel and Zürich Oerlikon railway station. The Hauptbahnhof was also connected via the Letten Tunnel to the Lake Zürich right-bank railway line to the southeast. This line also stopped at Stadelhofen station at the opposite side of the city centre, before passing through the single track tunnel to Letten station, then turning 180 degrees to reach the Hauptbahnhof. This line travelled 5 km to cover the 1.5 km distance between Stadelhofen and the Hauptbahnhof. Gold Coast Express The first step in developing Zürich's rail system which eventually led to the establishment of the S-Bahn was the establishment of the so-called Gold Coast Express (German: Goldküstenexpress) on 26 May 1968 between Zürich Stadelhofen and Rapperswil via Meilen along the wealthy north shore of Lake Zürich, popularly known as the Gold Coast. This development came about because, after World War II, there was a rapid expansion of commuting to Zürich from the former wine-growing villages along the railway line, which originally opened in 1894. As a result, commuters complained that the trains were overcrowded, slow and often delayed. The canton of Zürich began to develop a project to improve the railway in the 1950s. Because it was not used by either long-distance passenger or freight trains, improvements in local services were possible. Double track sections were built between Kuesnacht and