A driver said her "blood ran cold" after seeing a cyclist riding across the entire M60 carriageway.
The shocking dashcam footage was filmed at a particularly hazardous junction of the Greater Manchester ring road.
Junction 25 of the M60 is one of the few in the country where traffic from the slip road enters into the outside lane, containing the fastest flowing traffic.
The female cyclist, estimated to be in her twenties, who wasn't hearing a helmet, remarkably ignores all the warning signs and enters the carriageway before drifting across four lanes of traffic and the chevrons to the hard shoulder, where she carried on pedaling.
She even appears to put her hand out to thank the driver for letting her past - reports the Manchester Evening News.
Louise Kay, 48, was heading from work in Stockport back to her home at the the time of the incident last September.
She says she was forced slam on her brakes to avoid ploughing into the cyclist.
She has now shared the footage on Facebook to warn drivers of the potential hazards they can face.
She said: "It was just unbelievable, there's no other word for it, it made my blood run cold.
"I could see her out of the corner of my eye so started to slow down.
"And she just waved at me and carried on riding right in front of me. She honestly must have had a death wish.
"I shouted at her but she she had her headphones in and was just completely oblivious.
"She can't have not seen the signs and got confused as there's one up on Bredbury roundabout and another on the slip road itself and it's a good old run down to the motorway.
"Of all the places to do it as well with it going into the fast lane there."
Louise said she carried on driving and came off at the next junction but she thought by then it wasn't worth calling the police as she probably had gone.
However, she has shared the footage to a number of Facebook groups relating to motorway driving.
It is illegal for a cyclist to be on the motorway as under Highway Code rule 253 it is listed as a prohibited vehicle.
Culprits can be handed an on-the-spot fine if caught.
