Traffic information company Inrix said the accident led to delays on the M11, the A12 and the A406 North Circular.
The worst of the hold-ups were on the M11 and drivers were being advised to leave an hour extra for their journeys.
More top news
A 24-year-old man has been arrested on suspicion of murder after the body washed up on the Thames shoreline.
Seven people have now been arrested after a man died from serious head injuries
The 38-year-old officer was on his way home from a night shift when he collapsed. His death is not being treated as suspicious.