require no locomotive. One such multiple unit consists of 7 carriages and has a seating capacity of 480 passengers: 125 in first class, 332 in second class, and 23 in the dining car (which is part of second class). The fleet of ICN trains comprise 44 units. If needed, two ICN trains can be combined to double the passenger capacity. In addition, several type IV carriages can be attached to an IC 2000 train set on the other side of the locomotive, especially if a group reservation requires extra carriages. All carriages are air conditioned. Each train formation has first and second class carriages and, in most cases, a restaurant/bistro carriage. The availability of power sockets is constantly improved, sometimes even in second class. The maximal speed of all train types is 200 km/h, except for about half of type IV carriages that have not yet been upgraded and have a maximum speed of 160 km/h. InterCity trains serve most of Swiss cities and provide direct connections from Zurich and Geneva airports. The InterCity routes within Switzerland according to 2009–2010 schedule include: Lugano – Bellinzona – Arth-Goldau – Luzern - Zug – Zürich HB; Interlaken Ost – Interlaken West – ( Därligen – Leissigen – Faulensee ) – Spiez – Thun – ( Münsingen ) – Bern – Olten – ( Liestal ) – Basel SBB; Brig – Visp – ( Frutigen ) – Spiez – Thun – Bern – ( Olten ) – Zürich HB – Zürich Flughafen – Winterthur – Frauenfeld – Weinfelden – ( Sulgen ) – Amriswil – Romanshorn; Brig – Visp – Spiez – Thun – Bern – Olten – Liestal – Basel SBB; Chur – Landquart – Sargans – ( Ziegelbrücke ) – Zürich HB – Basel SBB; Genève-Aéroport – Genève – ( Nyon – Morges ) – Lausanne – Fribourg – Bern – ( Olten – Aarau – Lenzburg ) – Zürich HB – Zürich Flughafen – Winterthur – Wil – Uzwil – Flawil – Gossau SG – St. Gallen; as well as the following routes served by tilting ICNs: Bern – Zürich HB; Lausanne – ( Renens VD ) – Yverdon-les-Bains – Neuchâtel – Biel/Bienne – ( Grenchen Süd ) – Solothurn – ( Oensingen ) – Olten – Aarau – ( Lenzburg ) – Zürich HB – ( Zürich Oerlikon ) – Zürich Flughafen – Winterthur – Wil – ( Uzwil