Island dividing traffic gets railing (6)
I believe the answer is:
tirade
'railing' is the definition.
(railing against something)
'island dividing traffic' is the wordplay.
'island' becomes 'i'.
'dividing' means one lot of letters goes inside another (inserted letters divide the word).
'traffic' becomes 'trade' (I've seen this in another clue).
'i' placed into 'trade' is 'TIRADE'.
'gets' is the link.
(Other definitions for tirade that I've seen before include "A long abusive harangue" , "Speech of violent denunciation" , "A prolonged outburst of angry words" , "strong words" , "Long speech of angry criticism" .)