Police and paramedics have been called to the M60 in Stockport to deal with the incident.
One lane was closed between junction 1 and junction 27.
A police spokesman said: “At around 11.40am on July 6, police were called to … M60, Junction 1, Stockport.
“Emergency services are in attendance and the incident is ongoing.”
Traffic cameras show two patrols and two ambulances at the scene.