The state highway north of Kaikoura will reopen in December, after being badly damaged by the Kaikoura earthquake in 2016, and will restore the coastal link from Picton to Christchurch.
The NZ Transport Agency has confirmed plans to re-open State Highway 1 (SH1) on December 15, which will now give drivers two options when travelling around the upper South Island.
The alternate inland route has been used by motorists for the past year.
SH1 will still have several sites under construction when it re-opens next month.
The route will be closed at night in places for several months as a safety precaution, and planned closures will also be needed at times to carry out high-impact work, says NZ Transport Agency earthquake recovery manager Tim Crow.
"While we're re-opening SH1 as early as we safely can to provide better access to Kaikoura and for those communities along the coastal route, the full rebuild of the highway will continue in 2018," Mr Crow said.
The estimated time to travel between Picton and Christchurch on SH1 is expected to be a minimum of five and a half hours, while the alternate route takes a minimum of six and a half hours.