Siemens to provide signalling for Vienna metro Line U4 May 27, 2014 | Europe Company News Wiener Linien, the transport operator in Vienna, Austria, has awarded a EUR40-million contract to Germany-based Siemens to modernise signalling on Line U4 of the Vienna metro as part of the city&rsquo... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password