An interactive way of displaying the Berlin Ubahn system, based on this official map from 2016. Clicking on the stations, brings up wiki info about it.
I created the map using a modified version of d3-tube-map.
Even if the application only uses client side javascript, you still need to run a small web server to prevent CORS errors, because of loading json files from the local filesystem. A simple option would be Python's SimpleHTTPServer (or http.server, depending on the version of Python installed.). More about it here
> cd berlin-ubahn-map
> python -m http.server
Serving HTTP on 0.0.0.0 port 8000 (http:https://0.0.0.0:8000/) ...