Test perhaps after daughter becomes road user (6)
I believe the answer is:
driver
'test perhaps after daughter' is the definition.
I can't judge whether this definition defines the answer.
'road user' is the wordplay.
'road' becomes 'drive' (drive is a kind of road).
'user' becomes 'r' (I can't explain this - if you can you should believe this answer much more).
'drive'+'r'='DRIVER'
'becomes' is the link.
Can you help me to learn more?
(Other definitions for driver that I've seen before include "Type of golf club" , "Flat-faced golf club" , "See 1 down" , "Motorist - golf club" , "Member of RAC" .)