Its got a way to go but its getting there. The state took control of Belle Isle as a state park. Dan Gilbert and Roger Penske have dumped a bunch of money into restoration and repairs. I believe the roads are being torn up now for complete rebuilding.
Penske and Gilbert swear they will bring the F-1 series to town before they’re done.
https://www.youtube.com/watch?v=n1nQdRSYb94#t=106
Its going to be all new track next year.