Let's try the newer section of greenway trail. We can start at the Alcoa Municipal Building and take the bridge across the highway and see where the trail takes up. I have not tried this before, so can't tell you much about it.
Directions ... if you are coming from Knoxville, very shortly after you pass the airport the road splits. Go to the left at the split. Turn right at the first traffic light. Go to the end of the road and the Municipal Building is the last building on the left.
I will park behind the Municipal Building - so if you make a U-Turn at the end of the road and park just past the building coming back. There may be an opening to turn left into that parking lot without having to make a U-Turn, but I can't remember for sure.