A truck carrying an estimated 1 million chicken nuggets has crashed into a car and overturned on the Hume Freeway in Melbourne's north, causing traffic delays for 12 hours.

Police said the B-double with 20 tonnes of food was travelling south at Epping about 11:30pm when it hit an unoccupied car sitting in the emergency lane, crashed through a barrier and tipped over.

"The B-double has crossed onto the wrong side of the road, taken out centre barriers and has ended up sideways on the outbound lanes of the freeway," Sergeant Dean Pickering from Victoria Police said.

The truck veered through the barriers and onto the opposite side of the road. ( ABC News )

"We've had a pretty good outcome all things considered. The truck driver has very minor injuries, off to the Northern Hospital just for some observation but he's looking in pretty good shape.

"He had a small dog in the car as well and I'm happy to say that dog's doing fine, it's probably had the adventure of a lifetime."

Sergeant Pickering said it would have been "all over" if someone had been inside the demolished car.

No-one was in the car when it was crushed. ( ABC News )

VicRoads said the truck was carrying fish fillets and about 1 million chicken nuggets, and spilled 1,000 litres of diesel onto the road.

Recovery crews had to remove the boxes of food before they could get the vehicle upright and tow it away.

The northbound lanes of the Hume, which is one of the main arterials for Melbourne's northern suburbs and also to Sydney, reopened at midday.