Wiener Linien introduces digital PIS on Vienna U-Bahn, Austria January 21, 2022 | Europe News Wiener Linien has introduced a digital passenger information system (PIS) developed by Siemens Mobility for the X-car metro train set which will be deployed on Vienna U-Bahn Lines U1, U2, U3, and U4. ... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password