A second major motorway has closed, causing further traffic chaos for thousands.
Motorists are facing long delays on the M25 after a collision which came just hours after a fire forced the closure of parts of the M4 earlier.
National Highways confirmed traffic has been stopped anticlockwise along the busy stretch, between J18 and J19. 13:45 Sam Elliott-Gibbs
M25 delay latest
Motorists are likely to face delays on the M25 clockwise in Hertforshire until at least 2.15pm, National Highways has said.
The agency confirmed there are currently delays of around 40 minutes.
A crash took place between J18 and J19 just before 11.30am, causing one vehicle to overturn.
Traffic is tailing back two miles to before J17 for Maple Cross. 13:39 Sam Elliott-Gibbs
Traffic released on M25
Traffic