The A130 Colchester Road at Chelmsford is closed in both directions due to flooding between Drovers Way and the A12 Boreham Interchange.
The water at the roundabout by the entrance to the services is about 1ft deep and one vehicle has already become stuck.
Abellio, who run the Greater Anglia rail line, has been named Train Operator of the Year at the annual national Rail Business Awards.
Greater Anglia train operator Abellio says it's made real steps in customer service and punctuality in its first year in charge.
Greater Anglia have apologised for the delays that have disrupted services today