Those two tracks look pretty good still. Whats the history of the Ford test track?
Sort of an abondoned race track is the State Fairgrounds. They used to race GTP cars there back in the 80's. GTE cup or something like that. You can still see the start/finish line checkered paint in the parking lot.

Speaking of abandoned race tracks, there was a book written about it.
Auto Racing History Ghost Tracks Book Review