Drivers are being urged to leave extra time for their journeys this week due to ongoing work at Ringwood in Hampshire and Lancing in West Sussex.
Lane closures are in place on the A31 and the A27 because of ongoing work caused by flooding.
Lane 1 is shut on the A31 between Cadnam and Ringwood, so that contractors are able to clear flood water which continues to run off the saturated surrounding land.
Work is also being carried out by National Highways and UK Power Network for a power outage, also thought to be caused by flooding.
A lane closure is in place on the A27 near Lancing so repair work can be undertaken.
Highways England says all remedial work in relation to the flooding at this location are now complete.
Once work on the A27 and A31 are complete, Highways England said the roads will be fully opened.
Peter Philips, National Highways route manager said: “I would like to thank people for bearing with us while our teams have worked diligently on these flooding incidents.
"Aside from the volume of water on the carriageway, the low temperatures have caused the water to freeze creating a safety hazard.
"We expect the A31 to fully open soon and are supporting UK Power Networks with their work on the A27.”