It's thanks to the road worker (3)
I believe the answer is:
tar
'worker' is the definition.
(tar is a kind of worker)
'it's thanks to the road' is the wordplay.
'it's thanks' becomes 'ta' (UK informal version of 'thank you').
'to' is a charade indicator (letters next to each other).
'the road' becomes 'r' (this could be a standard abbreviation I've not previously seen).
'ta'+'r'='TAR'
Can you help me to learn more?
(Other definitions for tar that I've seen before include "Cigarette residue - old word for sailor" , "Sticky stuff for a kind of sailor" , "Black viscid substance" , "Viscous mixture - sailor" , "Informal sailor, the rat" .)