Good catch. I live in Berlin and use this sometimes, and I hadn't actually noticed that disclaimer before. (For future reference, it's under "Position der Fahrten" on [1].)

Munich's live S-Bahn map[1] takes a slightly different approach:

Um die Position der S-Bahnen auf der Karte anzuzeigen, werden die Positionsmeldungen der Züge an ausgewählten Signalstandorten erfasst und dazwischen hochgerechnet. Es handelt sich somit derzeit um keine GPS-Ortung.

(from "So funktioniert's" on [2])

So they don't actually use GPS positioning either, but they do interpolate from data that comes from their rail signalling system, which I imagine is a bit more precise than using realtime departures and arrivals in hh:mm.

[1] http://www.vbb.de/de/article/fahrplanauskunft/vbb-livekarte/...

[2] http://s-bahn-muenchen.hafas.de/bin/540/help.exe/dn?tpl=live...

[3] http://www.s-bahn-muenchen.de/s_muenchen/view/fahrplan/echtz...

Agreed, it's not really live, but still cool. There's a similar project for Swiss trains here: http://maps.vasile.ch/transit-sbb/

Source is available on Github (not my project).

The same thing exists for Austria as well: http://zugradar.oebb.at/

That shouldn't be a problem if the trains are on time.

That was either the best joke ever, or you haven't used German S-Bahn yet. (The "S" is supposed to be short for the German word for "city" but we jokingly refer to them as "standing still-train" instead of "city-train")

'Stand-Bahn'? Never heard that, although haven't lived in Berlin since before the 'meltdown' in 2008. Traditionally the S-Bahn is Berlin's favorite transit system (you can look out the window!), the most far-reaching, and the most interesting historically.

Although it has so many problems it's still my favourite method to get from A to B. Yes, windows, Internet, well spread out network. That's nice.

Actually I don't think it is 100% known what the "S" stands for. I think "Stadtschnellbahn" is most likely. The "Stadtbahn" only refers to the east-west route.

Good to know, because many towns have that I thought it's really Stadt-Bahn. Didn't know S5/7/75 have that special name.

maybe its like SOS and stands for nothing, at least at the beginning. It was used because it was easy to morse and not used ;)

You should travel more. You would never complain again. Berlin public transport is amazingly consistent compared to anywhere else I have lived (bar Singapore).

At least when I was in Berlin this September the U-Bahn worked perfectly.

even if they're running late it should be fairly accurate; there are no express trains here in Berlin so it's never very long since a train has been in a station for a positional fix.

Thats funny because I feel like I waited less time for trains to arrive in Berlin than I do in NYC (including express trains...)

Trains run every five minutes during normal business hours. It's great. Ten minutes at night, weekends, etc.