The M25 is blocked for a second day after a lorry veered into the central reservation then crashed and spilt cooking oil across the motorway.
The accident lead to three lanes initially being closed on the clockwise carriageway of the major road, just before Junction 25.
The junction - which is the turn off for the A10 at Waltham Abbey - was blocked off after the crash at around 11.30am yesterday morning.
Around 30 minutes later, the road was completely shut off to motorists because of the vegetable oil pooling on the road.
It has remained shut ever since and is likely to be shut through this morning's rush hour traffic (Wednesday, April 20).
Is the M25 motorway closed?
At the time of writing, the M25 motorway is closed but only between Junctions 23 A1(M) South Mimms and Junction 25 A10 (Enfield) clockwise.
Due to the complex nature of the clean up, the National Highways Agency expects it to remain shut throughout the morning.
Meanwhile, motorists using the motorway elsewhere are experiencing congestion, with queueing traffic for around three miles, according to the traffic monitoring system INRIX, Essex Live reports.
There is also congestion on the opposite side of the carriageway, back past Junction 25 due to onlookers on the anti-clockwise carriageway.
Traffic has built up for two miles.
Motorists should expect delays while clean-up efforts take place.
A diversion is currently in operation via the North Circular.
A spokesperson for National Highways said: "We are in the process of turning traffic trapped within the closure around.
"We have cleared all vehicles from J23 to J24 and are now starting to clear J24 to J25. ]
"Where you are in the queue will depend on how long it takes to be turned."
In their most recent update, they added: "The M25 clockwise remains closed between J23 (Borehamwood) and J25 (Enfield) following a collision and a large spillage of cooking oil across all of the lanes.
"Contractors are working to remove the oil from the carriageway.
"Delays of up to 60 minutes on the approach."
Motorists have been expressing their frustration on social media, according to Herts Live.
One wrote: "I've been stuck in stationary traffic between J24 and J25 since 11:30am.
"I have a screaming and v distressed 10 month old baby in the car who needs changing and feeding.
"What on earth is going on and when can I expect to be on the move?"