A woman is fighting for her life in hospital after suffering a medical episode behind the wheel.
The 64-year-old Meredith woman has been taken to hospital in Geelong in a critical condition following the incident, in which she ran off the road on the Midland Highway.
The car she was driving left the road just after 8am, just outside Meredith.
It came to rest near some trees, however it did not suffer serious damage.
Police said multiple witnesses saw the car leave the road and rushed to the assistance of the woman.
"We've got grave concerns for her health at this stage," said Moorabool Inspector Brendon McCrory.
"Multiple people have gone to her assistance and at this stage it doesn't appear to be an accident, but a medical epiosde."