The new route for Saddle Road has been graded and is about ready for pavement, federal and state transportation officials announced Thursday.
The grading work, which encompasses the first phase of the Saddle Road West Side project, involved 1.2 million cubic yards of material.
Major construction will begin in January with completion set for August.
The new segment will follow the existing road from the 41.5-mile marker for about a mile and then follow the course of an old Mauna Loa lava flow down to Mamalahoa Highway.
Kirkland Construction is working under a $33.7 million contract for grading, draining and erosion control or the 10.3-mile highway.
The project is on budget and six months ahead of schedule, transportation officials said.