Police were alerted at 1.35pm to a person spotted wandering across the Southern Motorway near Middleton, Christchurch.
Traffic had come to a halt on this part of the motorway as people tried to avoid hitting the pedestrian.
Police immediately attended the scene, picked up the person and took them home.
The traffic backlog was beginning to clear just after 2pm.
Police were unable to comment on the age or gender of the person involved.