A section of the anti-clockwise side of the M25 has been closed after a collision between two lorries left beer barrels and wood over the carriageway.
The vehicles crashed just before 06:00 BST between junction 17 for Maple Cross in Hertfordshire and junction 16 for the M40 in Buckinghamshire.
Thames Valley Police said there were no reported injuries.
The road is shut for “clean-up and recovery”. The Highways Agency said there were long delays in the area.
A spokeswoman said t was hoped the road would be open by 10:30 but one lane was likely to remain closed while recovery continued.