Motorists coming into St Peter Port from the west face diversions and delays while the Grange is resurfaced.
The work will take place in stages over 10 days and long diversions will be in force from Tuesday.
The north side of the road between Les Gravees and Brock Road and both junctions will be closed.
Motorists coming up the Grange towards the Rohais will be sent along Queens Road to the Mount Row - Kings Road junction and then through the Croutes.
There will be no exit from Queens Road into the Grange and traffic coming from Ville Au Roi will need to follow both diversions or use Prince Albert Road.
Access to Brock Road will be from the Doyle Road end.