Workers in race against time to get road open by weekend

Contractors racing to clear a slip that has cut off State Highway 1 at the Brynderwyns expect to have both lanes open in time for the weekend.

The underslip, about 20m long in the northbound lane on the south side of the hill, had fallen away leaving an 8m drop to the ground below and happened less than 48 hours after the reopening of SH1 south of Kawakawa following round-the-clock work on a temporary bypass.

The NZ Transport Agency said it plans to have SH1 on the Brynderwyn Hills re-opened to all vehicles tomorrow evening, weather permitting.

The hole the slip had created had now been filled and contractors were now repairing the patch of road, with a metal base, asphalt and markings still to be laid.

NZTA spokeswoman Jacqui Hori-Hoult said it had been earlier hoped one lane could have been opened this week, but detailed inspections indicated the under-slip was larger than first thought.

"We have removed the loose soil and are starting work to stabilise this section of the highway that encroaches into the southbound lane hanging over an 8m drop.

"It's just not safe enough to open even just one lane to light traffic."

There were two alternative routes available for all traffic travelling between Northland and Auckland.

People driving north were advised to use SH12 and the Paparoa-Oakleigh Rd, while those heading south could travel through Waipu and Mangawhai, with the detours adding between 30 and 40 minutes to travel times.