Blair Powell captured this video of a car running a red light onto a one way bridge, having to back off for an oncoming ute and then going down the bank.

A truck driver filmed in disbelief as a motorist ran a red light, reversed off a one-way bridge and then slid down a bank in Central Otago.

Truck driver Blair Powell, 32, of Gore, watched as the car reversed off the one-way Beaumont Bridge, on state highway 8. His video of the incident has gone viral, attracting over 470,000 views on Facebook and thousands of comments.

Powell was stopped at a red light on the bridge when the rental car ahead of him ignored the stop signal and drove on the bridge. A Hilux was coming towards the car and was not stopping.

Supplied The car ended up sliding down a bank.

The rental, occupied by two women, was forced to reverse back off the bridge.

"They were having some trouble reversing. The lights were coming on and off several times and they were running up the kerb a couple of times."

The car then reversed down the bank of the Clutha River.

"I stopped filming and jumped out to see if they were OK. There were two ... ladies in the car. They weren't that shaken. The passenger apologised to me. I was like, 'it's not my car, don't apologise to me'."

There was no cellphone coverage in the area so Powell called for assistance over his radio, he said.

"As a truck driver spending 13 hours on the road a day you come across some strange stuff. This was up there."