Police were called to an accident on the slip road to the A12 at Ardleigh.
The entry slip road at junction 29 was closed due to a two vehicle accident and because of flooding caused by the heavy rain.
One of the vehicles involved in the incident was a motorbike.
Traffic travelling from the Tendring area, heading towards Chelmsford, was diverted away from the slip road at 6.50am.
It was sent through Severalls business park to rejoin the A12 at the junction near the Weston Homes Community Stadium.
More follows later.