State Highway 73 will reopen to single lane traffic past the Otira slip tomorrow, but with delays, and the rail line is expected to open on Wednesday.

The NZ Transport Agency said its contractors had made good progress over the weekend clearing the significant slip that buried the highway and railway line near Deception Point, between Aickens and Otira.

About 9000 cubic metres of material was removed yesterday.

NZTA journey manager Lee Wright said the slip was far larger than initial estimates, and was now put at between 40,000 and 50,000 cubic metres.

Advertisement

From 8am on Tuesday the highway will reopen to one lane with 10-minute openings on the hour during daylight hours only, from 8am to 7pm. The road will be closed to all traffic overnight.

"This will continue for several days so crews can remove the remaining slip material and make the highway safe for two lanes of traffic again," Ms Wright said.

"People need to factor in extra time for this journey until we have both lanes safely reopened."

Kiwi Rail said it was hoping to reopen the Midland Line on Wednesday, although that was highly weather dependent. The Tranz Alpine passenger service is currently operating a daily return service from Christchurch to Arthur's Pass.

Intercity will put on a temporary bus service from tomorrow, through the Lewis Pass.

As the power lines were also taken out by the slip, the railway crossing warning lights in the Otira to Jacksons area are not operating and Kiwi Rail will be manually controlling these crossings when the trains resume.

"Slow down and be prepared to stop at all level crossings," Ms Wright said.

- Greymouth Star