Courage that may help motorist on winter drive (4)
I believe the answer is:
grit
This clue is a double definition.
'courage' is the first definition.
(I've seen this in another clue)
'that may help motorist on winter drive' is the second definition.
(grit can be put on icy roads)
(Other definitions for grit that I've seen before include "Fragments to sprinkle on roads" , "called for on icy roads" , "Hard particles for firmness of character" , "True determination?" , "Gravel or colloquial courage" .)