This channel posts very detailed videos about transit projects in the LA and SoCal region, and posted on today which included some things on Amtrak. Either way, I think anyone who supports transit, especially those in SoCal, should watch some of his stuff. Even if you're not in SoCal, understanding deeper into the subject of transit projects and what that means for us is great.
https://www.youtube.com/@nandert
https://www.youtube.com/@nandert