The M1 had to be closed southbound at Morisset for about four hours as emergency services responded to a serious truck crash.
A B-double crashed into the back of a slow-moving line marking truck near the Mandalong Road exit just after 11pm last night, blocking all southbound lanes.
It caused a large oil spill, with about 400 litres of diesel covering 300 metres of road.
Thankfully both truck drivers weren't injured.
Both returned negative breath tests.
The freeway was re-opened to traffic just after 3am.