Traffic controllers study directions (5)
I believe the answer is:
cones
'traffic controllers' is the definition.
(I've seen this in another clue)
'study directions' is the wordplay.
'study' becomes 'con' (con can mean to study).
'directions' becomes 'es' (east and south - two directions).
'con'+'es'='CONES'
(Other definitions for cones that I've seen before include "Cornets" , "Round shapes with tapering sides" , "Shapes of wafers for ice-cream" , "(Volcano) peaks" , "subject of a former hotline" .)