Is there a way how one can check the punctuality of Deutsche Bahn trains for dates in the past? I am looking for information about specific trains.
Have a look at zugfinder.net. It comes in a free and a paid version. For the free version you can see the data you need for the last month only. Simply enter the train number or station in the search fields on the left.
Not a direct answer, but a few avenues to explore further:
- DB has an open data portal with datasets and API's although it seems to be outdated.
- The question "Are there public transport data for Germany freely available?" on OpenData.SE
- If you can get your hands on GTFS-RT (real time) data of DB, you should be able to see how much delay each vehicle has. By storing that data periodically (or finding someone who has done so already) you can build a history and do analysis on that.
- Unfortunately this data seems not readily available. The Mobility Database for example has a wide array of links to GTFS-RT data, but it's missing data for Germany. If you find something, please do post that as an answer.
- Interestingly Motis, an open source multi-modal trip planner, shows info on real time positions of public transport vehicles in their routeplanner. Perhaps you can find where they pull this data from on their Github.