Waka Kotahi says a section of the Desert Road will continue to be closed during the day tomorrow, as repairs to a slip are taking longer than expected.
"While the rain forecast for Friday will slow contractors down, we're confident the work will be completed and the road reopened for the weekend," an agency spokesperson said.
The road between Rangipo and Waiouru was damaged in August and the slip edge has continued to deteriorate.
Detours are in place which Waka Kotahi estimates will add about 40 minutes to the journey. A further closure period is anticipated to take place late November or early December.