According to the Ōtaki to north of Levin April 2023 update:
Contractor Downer will start construction on the Pukehou turnaround location on the northbound side of SH1 on Wednesday 26 April. This work is expected to take six weeks to complete, depending on weather conditions.
While work is underway, a temporary road layout will shift both lanes to the east to ensure traffic can continue to flow. The northbound shoulder will be closed, and a 50km/h speed limit will be in place 24/7 for the duration of this work.
The construction team will be working between 7am and 5pm.
…Also on State Highway 1, maintenance nightworks at Ohau near the Marsden Terrace intersection are due to start on 1 May. Work will take place at night under a stop/go for two weeks, finishing Friday 12 May, weather permitting. SH1 will be open in both directions during the day under a temporary speed limit for the duration of this work.
