The male driver, who suffered from minor injuries, provided a positive breath sample at the scene of the crash between northbound junction 33 and 34 for Lancaster.
The incident, which happened at around 4:25pm, resulted in a full closure on the northbound carriageway from junction 32 at Broughton while police, air ambulance, land ambulance, and firefighters attended the scene.
A spokesman from Lancashire Road Police said: "The driver was arrested at the scene and the ambulance was escorted to Royal Preston Hospital by ourselves."
The crash caused tailbacks to junction 29 for Bamber Bridge, with traffic being diverted via the A6 for Garstang.
The motorway was reopened from 6:20pm.