State Highway 1 south of Kaikoura is open to all traffic between 6am and 8pm, Transport Minister Simon Bridges has announced.
The route has been shut since last month's 7.8 magnitude earthquake due to slips and damage to the road.
One part of the road remains single-lane and will be controlled by traffic signals.
"Re-establishing access to Kaikoura remains our number one priority," Mr Bridges said in a statement.
Transport Minister Simon Bridges in Kaikoura today.
Source: 1 NEWS
"Road crews have been working 12 hour days, seven days a week to get the highway south of Kaikoura re-opened in time for the busy holiday period."
"They've put in more than 10,000 hours of work over the last month to get to this point, removing more than 50,000 cubic metres of rock and material in more than 7,000 truckloads from 26 slips along the route."
'We are extremely excited'
District Councillor Derrick Milton said it was "seriously good news for Kaikoura", while Eve Parkin, who owns the Kaikoura Peketa Beach Holiday Park, said things had been desperate.
"We are extremely excited, today. I think (people will start coming back) - just look, isn't it beautiful?"
Earlier today, Mr Bridges had another up-close look at damage to SH1.
Transport Minister Simon Bridges and Associate Transport Minister David Bennett in Kaikoura after the announcement State Highway 1 south of Kaikoura will be open during the day.
Mr Bridges took an Air Force helicopter from Wellington with National MP and new Associate Transport Minister David Bennett, on the way inspecting slips and damage on SH1 north of Kaikoura.
It was Mr Bennett's first look at the damage.
"There's a bit of one there," Mr Bridges said to his colleague, as the helicopter circled a massive slip.
Fluro-clad workers came out onto the otherwise deserted road below.
Above another slip Mr Bridges pointed out a railway track that pointed out into the sea.
Source: 1 NEWS
He has previously said that opening SH1 access to the south would be a "huge relief" to locals and businesses, and allow visitors and tourists over the holidays.
The Government announced last week it would spend up to $2 billion to rebuild State Highway 1 and the rail corridor along the coastal route to the north and south of Kaikoura.
To rebuild SH1 in both directions would take about 12 months, Mr Bridges said at the time, and emergency legislation passed through Parliament this month would help cut through red tape and speed repairs.
An Order in Council has also been prepared, which will accelerate the rebuilding on SH1.
The inland road to Kaikoura - route 70 - opened to the public for unrestricted use this week.