for the S-Bahn. In the longer term, a vision for 2030 named Projekt S-Bahn 2G includes the development of two types of S-Bahn services and trains. Inner services will operate every 15 minutes, and will be provided by single-deck trains, so that passengers can embark and disembark quickly. Outer express services will operate every half-hour, stopping at all stations in the outer area but only at principal stations in the inner area, and will be formed of double-deck stock in order to provide more seating for longer journeys. In September 2014 a study was published for the construction of a new rail tunnel and underground station serving the ETH Hönggerberg "Science City". The new tunnel would run directly between Hardbrücke and Regensdorf stations, as opposed to the indirect route via the existing Käferberg Tunnel and Oerlikon station that is currently used by service S6. References Notes External links S-Bahn in Switzerland Regional rail in Switzerland S-Bahn 1990 establishments in Switzerland