The M6 was closed just north of Wolverhampton after a multi-vehicle pile-up involving three lorries and five cars on Monday.
The motorway was shut on the southbound carriageway between Junction 13 for Stafford South and Junction 12, at Gailey from early evening.
Congestion on the northbound carriageway, meanwhile, stretched back to junction 11 at Cannock.
Diversions also caused major traffic tailbacks on surrounding roads including the A449 at Penkridge and the A5.
The motorway is expected to remain blocked southbound for most of the night as recovery teams removed the vehicles involved in the pile-up.