The Transport Agency expects all repairs to the Manawatu Gorge to be finished next week.
That part of State Highway Three closed in August last year after a number of major slips.
A temporary road through the gorge, which opened last May, was shut weeks later after being washed away by rising river levels.
The route opened in August to one lane, and then to two lanes in September.
The Transport Agency says depending on weather conditions, a second coat of seal and new road markings will be finished next week.
Its says it is working with local councils to improve the Saddle Road, which was used as an alternate route when the gorge was closed.