Track state in progress (5)
I believe the answer is:
going
This clue could be a double definition.
'track state' is the first definition.
'going' can be an answer for 'state' (I have seen 'State of turf' mean 'going' so perhaps 'state' could also mean 'going'). I am not sure about the 'track' bit.
'progress' is the second definition.
(I've seen this in another clue)
'in' is the link.
Can you help me to learn more?
(Other definitions for going that I've seen before include "State of ground (racing)" , "in action" , "attending" , "Condition, of course" , "Ground condition for horse racing" .)