A woman is "lucky to be alive" after falling onto the M25 motorway in Surrey as she attempting to film a car journey using an app on her phone.

Surrey Roads Policing Unit (RPU) announced the remarkable story in a short post to Twitter where they described further details about the woman's miraculous escape.

A spokesperson for the road police said the woman, whose identity is unknown, had been using Snapchat video at the time of the accident.

"The front seat passenger was hanging out the car whilst filming a SnapChat video along the #M25.

"She then fell out the car and into a live lane," the Twitter post, which was liked and retweeted hundreds of times on Saturday, read.

"It is only by luck she wasn’t seriously injured or killed. #nowords," the spokesperson added.