Take her off the highway -- a dangerous driver (4)
I believe the answer is:
toad
'dangerous driver' is the definition.
(I've seen this before)
'take her off the highway a' is the wordplay.
I cannot quite understand how this works, but
'a' is within the answer.
The remaining letters 'tod' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for toad that I've seen before include "Common amphibian" , "Stout-bodied amphibian" , "Wind in Willows hall-owner" , "not found in Ireland" , "Contemptible person" .)