The road was closed just before 3am and lane three reopened an hour later, but traffic remained severe. All lanes reopened at 7.30am.
Drivers were advised to avoid the area this morning as some anticipated 60-minute delays to commuters' journeys.
Some were affected whilst driving on the M40, as queues backed up at J1. M25 anticlockwise from J16 M40 and M4 in to town was busier than usual as people were diverting away from the delays.