The 50-year-old woman, who was believed to have been travelling from Cheltenham to Rushworth, was airlifted to the Royal Melbourne Hospital after hitting a tree on the Heathcote-Rochester Road. 

Her Mazda hit the tree on the driver side door around 9.10am deploying the car’s airbags. The front end of the vehicle received significant damage. 

The woman was the only occupant in the northbound car and Senior Sergeant Paul Gardiner said she appeared to have swerved before leaving the road. 

“It’s hard to say what’s happened,” he said. 

“As far as where we sit with the investigation, we need to establish why the car has gone heavily, or violently, off the road to the left and collided with the tree. 

“That will take some time to establish.

“Experience tells me the vehicle has drifted off the road one way, to then get back on to the road, then the vehicle grips and pulls back off the road again.”

The force of the impact stripped bark off the tree and items from the car were scattered around the site. 

Senior Sergeant Gardiner said the road wasn’t known to be especially dangerous, but said all country roads had a high risk of car accidents. 

“It’s a fairly standard rural road that we have in central Victoria,” he said. 

“We had a campaign a couple of years ago about country roads and about people dying and getting seriously injured on country roads. 

“If you look at this backdrop, that’s exactly the backdrop used in that campaign with this type of road, these types of trees. 

“We always encourage people to just remain vigilant.”

Senior Sergeant Gardiner said police could not rule out that the driver had swerved to avoid a kangaroo or other wildlife. 

He said the driver had severe pelvic and lower body injuries. 

She was airlifted to the hospital at about 11am and a section of the road was closed to traffic for about two hours. 

The crash followed a two-person fatality at the nearby Northern Highway in February.