Macquarie Pass will close next week for essential maintenance.
The road will close in both directions from 7am on Tuesday until 4pm on Wednesday.
During this period, detours will be in place via Jamberoo Mountain Road for light vehicles, adding about 10 to 20 minutes to journey times.
The detour for heavy vehicles will be via the Hume Highway, Picton Road and the M1 Princes Motorway. Drivers should allow an additional 90 travel time.
Access to residents will be maintained and businesses on either side of the Pass will remain open.
The work involves replacing a drain underneath the road, inspecting the road surface for faults and impending problems, managing vegetation including pruning trees and controlling weeds and collecting rubbish.
Macquarie Pass is scheduled for essential maintenance every three to four months.