Lane three has been closed between junctions 34 (Bay Gateway, Lancaster) and 35 (A601, Carnforth) following the crash.
Traffic is coping well in the two open lanes and Highways said it expects to open the third lane by 8.20am.
A pot hole has also led to a lane closure between junctions 37 (Kendal, Sedbergh) and 38 (Brough, Appleby) on the northbound carriageway.
It is being repaired by maintenance crews and traffic officers are at the scene to enforce reduced speed limits on approach.