Road rage can be a hallucination! (6)
I believe the answer is:
mirage
'a hallucination' is the definition.
(thesaurus)
'road rage' is the wordplay.
'road' becomes 'mi'.
'mi'+'rage'='MIRAGE'
'can be' is the link.
(Other definitions for mirage that I've seen before include "Something illusory and unattainable" , "image, not what it seems" , "Illusory image" , "Optical illusion caused by atmospheric conditions" , "fighter craft" .)