State Highway 1, south of Kaikoura, will be closed to all traffic from March 26 to April 4 to enable emergency slip face stabilisation work to be carried out.
The closure will allow the removal of loose rock and debris from 12 slips between Goose Bay and Peketa, improving safety and helping to reduce closures during winter.
NZ Transport Agency earthquake recovery manager Steve Mutton said the work has become "critical" follow the heavy rain the area has experienced recently.
"New slips along the route mean that we have repeatedly had to close the highway, disrupting travel," he said.
"We are working with residents who live along this section of the highway to provide limited access during this time and we will retain emergency access at all times."
Kaikoura will be accessible by the inland road via Culverden and Waiau, which has remained open during the recent wet weather.
"Road works are being carried out along this route to ensure it is in the best possible condition before the start of winter so everyone is asked to take extra care and allow plenty of time for their journey," Mr Mutton said.
Average journey times from Christchurch to Kaikoura on the inland road are about three to three-and-a-half hours.