Road crews will be carrying out work on Lawrence Hargrave Drive next week in preparation for the planned closures in 2020.
Next year, the stretch of Lawrence Hargrave Drive from Stanwell Park to Bald Hill will be closed for two one-month periods to allow for slope stability work.
Transport for NSW's preference is for the road to be closed 24 hours a day but it has decided to encourage tenderers to consider options that could see the road partially opened.
Ahead of that work, crews will be undertaking investigative work on Lawrence Hargrave Drive between Otford Road and Chellow Dene Avenue.
The work will take place on September 16 between 9am and noon and will one lane will be closed, with alternating traffic flow and a reduced speed limit of 40km/h in place.