A video released as part of the Christchurch Dilemmas series shows the massive scale of repairs to quake-damaged State Highway 1, north of Kaikoura.
Nine slips were caused by the magnitude 7.8 earthquake in November, which blocked what was the main route from Picton to Christchurch.
The six minute video from the creators of When a City Falls interviews workers on the northbound part of the highway, which is due to open on December 15.
"It would have to be the biggest job in New Zealand," site supervisor Peter Thompson said.
"Pictures and paper clippings don't do justice, until you can see it first hand."