I’ve maintained a Transit Calendar on this blog for about ten years. It’s useful in that it’s edited. I enter the events by hand, excluding the minutiae. I also link relevant content to most of the entries.
The import (to Google) function has been broken for years. I’ve had no earthly idea how to fix but as of today, I can tell you that if you click an event and then click “Google Calendar”, it will add that particular event to your calendar. For some, this might be ideal.
As for importing the entire calendar, I am able successfully import the .ics file, but the events don’t show on my Google Calendar and I don’t know why.
I also tried to import the entire calendar using the url (Settings -> Add Calendar -> From URL.
This worked, but it only imported two weeks of events.
I’m posting this in case someone has figured this out. People email me about this pretty frequently. It would be nice to have a solution. Thanks!