Commuters are facing long queues on the M25 on Thursday morning with a crash at the Dartford Tunnel shutting the key route.
Congestion is building after the crash anticlockwise between J1A (Dartford) and J31 (Lakeside / Purfleet).Meanwhile motorists are facing nine miles of tailbacks on the M25 further north in Essex due to reports of people on the road.
A lane of the motorway was forced to close anticlockwise near Brentwood and Brook Street Roundabout, according to travel data site Inrix.
Traffic was queuing before Junction 29 at Romford and back along the A12 Brentwood Bypass.
On the railways, Avanti West Coast train services into London are suffering serious disruption. A number of services into London Euston have been cancelled due to a shortage of crew.
Passengers on the Tube face further strike disruption with Aslef announcing two one-day walkouts on Monday, April 8 and Saturday, May 4.
The union also announced train drivers at 16 rail companies are to stage a fresh wave of strikes and a six-day overtime ban in a long-running dispute over pay, threatening more travel chaos for passengers across the country.
