Police were called at 12:50pm.
Both lanes of the eastbound carriageway were blocked between Dacre and Stainton.
A Cumbria Fire and Rescue Service spokesman said: “At 12:53 firefighters were called to a report of a road traffic collision on the A66 near Stainton.
“Crews used hydraulic cutting equipment and small tools.”
Update: All lanes have now reopened.