In 2005, media IT student Christian Bode developed this fake subway system for Bremen as a Bachelor project, including a corporate design study and a website with line maps, fare information, a working trip planner, tourist information and company history.
The (german language) website can be found in the internet archive
https://web.archive.org/web/20051124212728/http://www.die-bremer-ubahn.de/The current site is somewhat unmaintained, broken and misses a lot of the fake information.
