The M25 in Essex is closed in both directions between J23 (A1) - J27 (M11) clockwise, and J27 (M11) - J25 (Cheshunt) anti clockwise. The carriageway may not fully reopen until 3pm.
Motorists are being told to stay away from the M25 in Essex. Emergency services warn the carriageway could be closed for the rest of the morning and possibly into the afternoon.
Hundreds of drivers are facing long delays today as the M25 in Essex remains closed.
The M25 in Essex is closed in both directions between J23 (A1) - J27 (M11) clockwise, and J27 (M11) - J25 (Cheshunt) anti clockwise due to an incident. Early estimation is that both carriageways are likely to remain closed throughout the morning.
Diversion routes are in place.
Clockwise: road users may exit the M25 at junction 23 and follow the A1 southbound. Then join the A406 North Circular Road towards the M11. Join the M11 northbound, to re-join the M25 at junction 27.
Anti-clockwise: road users may exit the M25 at junction 27 and follow the 'hollow black square' diversion signage via the M11 southbound. A406 westbound and the A10 northbound.
Traffic approaching from Kent and Sussex wishing to travel to the North is advised to use the M25 clockwise.
Traffic approaching from the North (M1, A1, M40 etc) wishing to travel to Kent and Sussex is advised to use the M25 anti-clockwise.
Investigations are continuing and police are also working with the Highways Agency to clear the carriageways of debris so that repairs and resurfacing can be carried out.
No definite time for the reopening of the motorway can be set yet but it is likely to remain closed throughout the morning rush-hour.
Part of the M25 has been closed following a fatal crash. One person was killed and three others were taken to hospital following the accident at 1.50am today in Essex.
The motorway is still closed between junctions 25 and 27, and is likely to remain shut for most of the morning.
Plans to unveil a two billion pound boost to improve roads across London and the South East will be unveiled by the government later today.
The money will go towards expanding junctions on the M25 as well as building a new bypass on the A27.
Work began at 6am today to remove 27 toll booths on the southern end of the Dartford Crossing.
The booths on Britain's busiest motorway are being scrapped and replaced with an electronic payment system.
The changes at the Dartford Crossing on the M25 east of London are designed to improve traffic flow.
But the removal of the 27 toll booths at the southern end of the crossing will result in roadworks until March 2015.
And car drivers using the crossing will from today face a higher daily charge - with the fee, also payable by phone or post as well as online, going up from £2 to £2.50. Charges are also rising for goods vehicles.
The Highways Agency is hoping for a minimum of congestion at the start of the new system.
An agency spokesman said: "We're starting at 6am on a Sunday when traffic will be comparatively light and there will be plenty of signs up to tell people about the new arrangement.
"Monday morning will be more of a test but we are trying to do everything we can to let people know about the changes."