A spokesman from the Highways Agency has confirmed major works on the A27 have been delayed by heavy rainfall this week.
However, the exact delay to the drainage improvement works around the Chichester bypass has not yet been released by the agency.
The A27 eastbound was closed from Portfield Roundabout to Tangmere from Sunday, February 10, until Tuesday afternoon, causing disruption for commuters and drivers.
Delays have also been reported on the westbound carriageway between the A285 Halnaker and the A285 Chichester due to flooding.
The road improvement scheme is estimated to cost in the region of £70million.