A THREE-month programme of work on the A27 Chichester Bypass is set to start on Monday, November 26.
Drainage work will be carried out on the bypass from Portfield Roundabout to Fishbourne Roundabout and is scheduled to finish in late February.
There will be a break over Christmas when all lane restrictions will be removed.
During the day, there will be narrow lanes on the dual carriageway with a 40mph speed limit.
At night, between 8pm and 6am, there will be lane closures.
There will be full road closures when narrow lanes are being removed and installed.
At the moment, these are planned overnight for November 26 and 27, December 20, January 3, 4 and 5, and February 8 and 9.
A Highways Agency spokesman said the work would help to combat the history of dual carriageway flooding in the area.
A public information event will be held at Westgate Leisure, Chichester, from 4pm to 7pm on Tuesday (November 20).
Anyone who would like more information can visit www.highways.gov.uk
The Highways Agency has also set up an online survey, which will be open from now until the roadworks are complete.
It is available to view at www.surveymonkey.com/s/A27Chichesterdrainage.