On the railway networks operated by the Deutsche Bahn (DB), the Austrian Federal Railway (ÖBB) and the Swiss Federal Railways (SBB) today, express trains are divided into categories such as Eurocity, Intercity, Interregio etc. The DB still occasionally runs "D-Zug" services in night trains ("D-Nacht"), especially those to its eastern European neighbours, and as relief trains. Museum services running on DB routes are also given "D-Zug" numbers. ÖBB runs D-Züge on main routes from/to Vienna on weekends and during rush hours.