Traffic controller caught individual (4)
I believe the answer is:
cone
'traffic controller' is the definition.
(item used to direct or control traffic)
'caught individual' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'individual' becomes 'one' (an individual is one person).
'c'+'one'='CONE'
(Other definitions for cone that I've seen before include "may obstruct lane" , "Movable plastic bollard" , "Portable marker for lines on road" , "Circular pyramid" , "Volcanic peak" .)