Queues formed on the motorway near Rishworth Moor.
Sahrah Khan tweeted: "M62 crash air ambulance and traffic complete stand still!! #M62crash."
She told The Yorkshire Post: "Two ambulances arrived. [I was] allowed to slowly drive off I saw one car which was clearly damaged at the back left side with the wheel totally uncovered as the body work had gone. Same car damaged at front right side so guessing was hit from behind as well as hitting someone in front."
Transport for Greater Manchester said there were two to three lanes "blocked on the M62 Eastbound at Junction 22-24 due to a RTC. This is causing delays on the M62 Eastbound to Junction 19, back past Rochdale.
"Please allow extra time for your journey and if possible use an alternate route
Yorkshire Air Ambulance has been approached for comment.