Roads and Maritime Services (RMS) advised motorists of changed traffic conditions on the Kings Highway at Nelligen from Monday, November 11.
Work on utility relocations is due to start as part of the Nelligen Bridge replacement.
An RMS spokesperson said the north-western entrance into Thule Road will be closed at various times for about ten weeks while the work is carried out.
"Motorists are advised to use the south-eastern entrance into Thule Road," the spokesperson said.
Work will be carried out on weekdays between 7am and 6pm and from 8am to 1pm on Saturdays. No work will be carried out on Sundays or public holidays.
Traffic control and a reduced speed limit of 40km/h may be in place at different times around the Nelligen Bridge for the safety of workers and road users.
Motorists are advised to drive to the conditions, and to follow the directions of signs and traffic control.
"Some activities will also be carried out on either side of Nelligen Bridge to drill holes and install utility pipes under the Clyde River," the spokesperson said.
"Some areas may be temporarily fenced off however the playground and toilet facilities on the western side of the river will remain open and no traffic impacts are expected in this area.
The spokesperson said no work will be carried out over the peak holiday period from Monday, December 20, with work recommencing on Monday, January, 6, to minimise the impact to motorists and the community.
"Transport for NSW has been working on further improvements to the detailed design which will be finalised prior to the assessment of construction tenders in preparation for upcoming major work," the spokesperson said.
"Transport for NSW thanks the community for its patience while work is carried out."
For the latest traffic updates call 132 701, visit livetraffic.com or download the Live Traffic NSW App.
For more information on the project visit rms.nsw.gov.au/nelligenbridge