NZ Transport Agency Waka Kotahi will begin clearing the roof of the Rock Shelter on State Highway 73 between Otira and Arthur’s Pass starting Monday, 9 September.

This work will result in temporary changes to the road’s operating hours, subject to weather conditions.

The road has been closed at night for the past two weeks due to a rockfall caused by snowmelt and heavy rain.

The upcoming work aims to remove the debris accumulated on the Rock Shelter roof to restore the structure’s operational performance and ensure safety for travellers.

Maintenance Contract Manager Moira Whinham said, “To do this work requires large machinery taking up the full road width in this narrow part of the Otira Gorge.

SH73 between Otira and Arthur’s Pass will need to be closed for four hours initially, then after that, closed openings on the hour for traffic to get through.”

The first closure is scheduled for Monday, 9 September, from 10 am to 2 pm to lift an excavator onto the Rock Shelter’s roof.

If weather conditions are unsuitable, this will be rescheduled to the next dry day.

Starting Tuesday, daily closures will be in effect from 9 am to 5 pm, Tuesday to Friday, with the road opening on the hour to allow traffic to pass.

No work is planned for Saturdays or Sundays, and the road will remain open during the day from 7.30 am to 5.30 pm.

The road will continue to be closed overnight between 5.30 pm and 7.30 am until the site is deemed safe.

Whinham said that the work is weather-dependent, and road closures may change at short notice. “We appreciate people’s patience while we progress this work as quickly as possible,” she said.

Travellers can check the latest route availability and updates on the NZTA Journey Planner website.

Electronic signs at key locations, including Kumara Junction and Springfield, will display daily open hours.

The work is expected to take up to six weeks, weather permitting, and updates will be provided each Friday to outline the following week’s closures.

Additional maintenance work on SH73 may also affect travel times, so travellers are advised to plan accordingly.

For those wishing to avoid delays, an alternative route is available via the Lewis Pass (SH7), adding approximately one hour to the journey between Christchurch and the West Coast.

“We understand that this work is disruptive and appreciate people’s understanding while we make this site safe and get the highway back to normal operations for the summer,” said Whinham.