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
Vlogging from her home in London she has become a YouTube sensation, so successful she has just published her first book.
Health union workers were due to walk out on Thursday in a dispute over pay.
Rail services through Farringdon are being delayed again tonight as engineers carrying out safety checks.