This is the moment a driver on the M5 captured what he believed to be "racing" vehicles travelling along the motorway.
Milo Sirrom was driving along the southbound carriageway of the motorway when one car used the hard shoulder to undertake him - before a second went past him at speed using the middle lane.
Mr Sirrom's dashcam captured the incident - which you can watch above - near junction 23 for Bridgwater.
Somerset Live reports Mr Sirrom has passed the footage on to Avon and Somerset Constabulary.
Have you captured poor driving on dashcam? Send it in via bristolpostnews@localworld.co.uk
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In the footage, a black Seat Leon and a blue Volkswagen Golf appear to be travelling at very fast speeds on the motorway. They can be seen weaving in and out of traffic, with the Seat emerging from the hard shoulder at the beginning of the video.
On Facebook Mr Sirrom wrote: "[I witnessed] the most dangerous driving I've ever seen on the motorway.
"I've uploaded the footage to the police.
"If this was you driving, I hope you are pleased with your driving skills you wannabe racing drivers."
Underneath the post, an M5 driver added: "Why do these idiots think they have the right to risk other people's lives?"
While another wrote: "Oh my god they were racing each other, on the hard shoulder as well.
"I hope the police sort it out. It's scary."
And a third person wrote: "Utterly crazy.
"I'm certainly glad that there were no road workers working on the hard shoulder."
