One big reason tracks are closing down, at least in CA, is property value. The land these tracks are on is worth waaaaayyy more as residential, commercial, or retail property, than what they bring in as a private race track. It just doesn't make financial sense to maintain the land as an operable race track. Add to that population growth/urban sprawl and pressures from local officials, and I can totally understand why a track owner would say **** it.