51–60 of 143 posts
I'm glad they use OpenStreetMap instead of Google Maps. Well done.
Earlier quoted context omitted.
According to the website, the location information isn't exact, but "calculated" (whatever that means).
Ah. So no use in real-time if there is an unplanned delay as the map will show that the train just went past you when in fact it didn't. Shame.
As far as I understand the technologies (and I assume that Berlin does the same thing as every other city-user), a precise ("physical") GPS position is usually not reported (although newer systems do that as well), but a position at a "logical" map is. In case of buses, this usually means "left the previous stop at $xx:$yy, with $zz seconds of delay; reported average speed is normal for this area, so expected arrival is at $aa:$bb." In case of trains, the usual reported data is "has left section of track $AA, is now at $BB, delay $x seconds, expected at $CC in $yy:$zz".
Not millisecond-perfect, but fairly precise to about a minute or two; the biggest guesstimate is the exact position (you'll see that all the trains seem to be using a single track, where in reality they would be on different ones).
So, while delays are reported near-realtime (and thus the scenario you describe doesn't happen), the map might be inaccurate if the route needs to be changed (e.g. there's an accident blocking the road and a bus needs to take the next street instead). Again, with the rollout of GPS-equipment across fleets, this becomes less of an issue. Btw, most delays are unplanned ;)
This appears to use the theoretical schedule, rather than real-time information. I live next to a busy tram line, and what I see through the window does not match what the site shows.
"VBB-Livekarte zeigt berechnete Positionen der Fahrzeuge zwischen zwei Stationen; falls kein Live-Fahrplan vorhanden, dann Position gemäß geplanten Fahrzeiten"
Translation:
It shows the calculated position of the vehicles between two stations. If there currently is no live data it shows according to schedule.
http://www.vbb.de/de/article/fahrplanauskunft/vbb-livekarte/...
This appears to use the theoretical schedule, rather than real-time information. I live next to a busy tram line, and what I see through the window does not match what the site shows.
Totally, buses never seem to stop at traffic lights.
> VBB-Livekarte zeigt berechnete Positionen der Fahrzeuge zwischen zwei Stationen; falls kein Live-Fahrplan vorhanden, dann Position gemäß geplanten Fahrzeiten
Earlier quoted context omitted.
I thought the same. But I can't actually come up with a good reason. Maybe German trains are so punctual that you can infer their position anyway. Can someone in Berlin measure the lag? Next time I'm back there I might test it.
I can only speak for Berlin and will say punctuality is not the strong point of S or U-bahn here.
There is a similar tool for the whole world created by a german student a few years ago - http://tracker.geops.de - albeit without RT data for berlin because apparently they dont have access to it. But they do have RT data for the netherlands.
We are using the same method as the VBB - interpolated timetable data augmented with station-based delay-information where available.
Tallinn, Estonia: http://soiduplaan.tallinn.ee/#tallinna-linn/map/en I made simpler map for my personal usage. http://siim.planet.ee/yhistransport-live/