A lorry jack-knifed on the M25, closing the motorway and causing delays during morning rush hour.
Highways England warned motorists to "plan ahead" after the motorway in Essex was shut following the crash.
It said delays were being experienced around the area of the Dartford Tunnel during rush hour.
The four-lane motorway was closed on the anti-clockwise carriageway for about three hours following the crash, which happened at 02:45 GMT.
Two lanes remained closed until about 08:00 as police attended the scene, between junction 30 for Tilbury and Lakeside and junction 29 for the A127.
After the motorway fully reopened, Highways England said in a tweet that delays were being experienced on the approach to the Dartford Tunnel.
It said: "All lanes are now open however long delays remain on the approach to #A282 #Dartford #DartCharge.
"Please plan ahead if travelling in the region."
Essex Police said there were no serious injuries reported.