Traffic conditions have returned to normal after an oil spill on Bulli Pass on Friday afternoon.
Fire and Rescue NSW and Rural Fire Service crews were called about 1.30pm to a report of an "oil slick from the top to the bottom" of the pass, a spokeswoman said.
Authorities directed motorists into a stop/slow traffic flow while the spill was being cleaned, with traffic returning to normal just before 2.30pm.
RFS and Roads and Maritime Service crews spread an absorbent agent over the oil spill, which soaked up the liquid. It was then swept up and hosed for a final clean.
An RFS spokesman said a truck driver had likely overfilled the petrol tank and as the truck travelled down the hill, small drops of diesel ran out on the bends.