Construction begins on Frankfurt U-Bahn Line U5 extension, Germany September 22, 2017 | Europe News Construction work has begun on U-Bahn Line U5 extension in Frankfurt. The light rail extension will span 2.7 km (1.4 km underground, 1.3 km over ground) from the city centre to Europaviertel, covering... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password