Contractors have continued their work overnight on a 100 metre-long detour to bypass the SH1 slip at Maromaku.
The NZ Transport Agency said damage from the recent storm is so extensive it may take some time to fully restore the region's roading network.
Work on SH1 has seen vegetation cleared near the site and work has started on the construction of the diversion. Officials hope if the weather remains favourable the bypass could be opened by the end of the week.
Transport Agency's Regional Journey Manager Jacqui Hori-Hoult said they had to be absolutely sure the ground was stable enough to safely open the by-pass around the washout.
The main alternative route for all vehicles between the Far North and destinations further south remains SH12 through Dargaville and Kaikohe.