Motorists are facing around 10 miles of tailbacks around the Dartford Crossing on the M25 clockwise after a vehicle fire.
All lanes were stopped at 10.25am on the M25 clockwise from junction 1a (Swanscombe) to junction 1b (A296 Princes Road, Dartford).
By 12.35pm all four lanes had reopened.
Queues built around the Essex - Kent border after authorities closed the road at around 10.25am.
Elsewhere, traffic was queuing for around four miles on the M25 anticlockwise near Waltham Cross, north London, on Friday due to road works.
The slow moving congestion stretched from junction 26 (Waltham Abbey) to junction 25 (A10 Enfield) around a construction area, according to live data presented by Inrix.
On the Tube, the Northern line has had severe delays after a fire alert at Colindale.
There is no Overground service between West Croydon and Sydenham due to signal failure. The disruption is expected to last until 3pm.
All other lines are operating a good service.
