Crush? Go faster, avoiding it (4,2)
I believe the answer is:
step on
'crush?' is the definition.
(I've seen this before)
'go faster avoiding it' is the wordplay.
'go faster' becomes 'steponit' (I've seen this before).
'avoiding' is a deletion indicator.
'steponit' with 'it' removed is 'STEP ON'.
(Other definitions for step on that I've seen before include "Behave harshly towards" , "crush" .)