[wahsd]

No, they didn't simply have to connect some disconnected lines. Not only did the eastern infrastructure, have to largely be rebuilt from the ground up, but even the western part was outdated and old and reunification meant that billions were spent on upgrading infrastructure.

[mmaldacker]

Upgrading and maintaining a transport infrastructure is necessary for big cities regardless of the wall circumstances. You don't think London, Paris and other big metropolitan cities in Europe spend billions on upgrading and maintaining their public transport infrastructure? I don't see Berlin having a completely automated metro like the DLR in London, or NFC cards like pretty much any other metro in Europe.