Frightening dash cam footage has shown the moment a truck takes out a car in its blind spot while changing lanes in regional Victoria.

The video has sparked an online debate as to who’s at fault, with some saying the car shouldn’t have been in the truck’s blind spot in the first place.

“Do not sit in a truck’s blind spot, it’s not rocket science, it’s common sense,” one Facebook user said.

"Either stay way behind the truck or get way out in front quickly. Yes the truck hit the car but the car driver was clueless for not driving defensively,” another wrote.

Others jumped to the defence of the driver.

“I’m not sure why people think colliding with a vehicle because it's 'in your blind spot' is some kind of defence for your actions ... You ALWAYS make sure the lane is free and safe BEFORE merging.”

"As a truck driver I’d be the first to stick up for them. But here it’s clear the B-Double is 100 per cent at fault! Although the car is in his blind spot he would’ve seen that car come up past him at some point."

The incident happened last Saturday on a rainy day on Geelong’s Ring Rd. The woman in the car was reported to be in shock from the ordeal but didn’t suffer any serious injuries.

Who do you think is at fault?