This trail goes right through the heart of Ferguson and it is very flat and very well maintained. I think the signs said it's closed after sunset. Anyway, it was a beautiful walk mid-day and mid-week and I didn't encounter anyone. I think there's a lot of caution about this trail because of events in 2014, but I didn't see anything to worry about. I really liked that there were almost no street crossings.
There are two tunnels, the first very close to the UMSL campus. It's pretty short, more of an underpass. There's a longer tunnel that I assume would be creepy late at night in the dark if you're walking alone, but during the day it was fine and it did have fluorescent lighting.
It connects to other pathways near UMSL and a lot of the new architecture around campus is very pretty, especially the ponds near the Millenium Student Center which would be a good place to stop and cool off, get a bite to eat (during school year normal working hours primarily).