Berlin Hauptbahnhof: U55 shuttle train at underground platform

A bright yellow U55 shuttle train is shown at the underground platform of Berlin Hauptbahnhof, the city's main railway station. This short-lived U-Bahn line, operational from 2009 to 2020, served as a vital link between the Hauptbahnhof and the government district at Brandenburger Tor. Its integration into the extended U5 line in December 2020 marked a significant step in Berlin's east-west metro network expansion. The platform features a network map of the S- and U-Bahn lines, indicating its role within the broader public transportation system.