Deutsche Version
The network overviews are not longer maintained. Google MyMaps is unsuitable for editing and an other solution for editing and viewing is not in sight.
Switch layers
Click or tap on the 
-icon in the top left corner of the map to show and hide the different layers and
to switch between map and aerial view.
-icon in the top left corner of the map to show and hide the different layers and
to switch between map and aerial view.
key
route in use (overground)
route in use (underground)
non-revenue route
abandoned route
route under construction
route planned