Marks the road surface obtains (7)
I believe the answer is:
targets
'marks' is the definition.
(I know this)
'road surface obtains' is the wordplay.
'road surface' becomes 'tar' (I've seen this in another clue).
'obtains' becomes 'gets' ('get' can be a synonym of 'obtain').
'tar'+'gets'='TARGETS'
'the' acts as a link.
(Other definitions for targets that I've seen before include "Goals" , "Aim points" , "Reference points to shoot at" , "objectives of firing people" , "Butts" .)