Crossing states after turning right before Alabama (9)
I believe the answer is:
traversal
'crossing' is the definition.
(I know that traversal is a type of crossing)
'states after turning right before alabama' is the wordplay.
'states' becomes 'avers' (to aver is to declare or state).
'after turning' shows that the letters should be reversed in order.
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'before' is a charade indicator (letters next to each other).
'alabama' becomes 'al' (abbreviation).
'rt' reversed gives 'tr'.
'avers' after 'tr' is 'travers'.
'travers'+'al'='TRAVERSAL'
(Other definitions for traversal that I've seen before include "A journey across" , "Action of crossing" , "Coming across" , "Act of crossing" , "crossing over bridge" .)