Your track is not ‘solid’, if it were solid then if you selected it Entity Info would report it as such and show its volume in the model’s current units.
If you use a tool such as thomthom’s Solid Inspector² it will shown the many issues preventing it becoming a ‘solid’.
There are several nested groups inside it, which need exploding.
There are some unfaced edges and many edges with only one face [a solid needs every edge to support exactly two faces - so internal ‘partition’ faces are not allowed as their edges will have more than two faces].
There are a lot of reversed faces - view it in Monochrome mode to see the blue-gray faces - every visible face should be ‘white’ - that alone doesn’t stop it reporting as being solid but it could cause issues relating to ‘volume’ calculations later.
You need to do some more work on it to get it into a ‘solid’ state to get a volume…