The government is to spend more than $230 million improving State Highway 1 on either side of Kaikōura and creating a new cycleway.
The New Zealand Transport Agency Board has approved the changes for a 60km section between Oaro in the south and Clarence to the north.
Transport Minister Simon Bridges said the money was in addition to the $812m reinstatement package announced in this year's Budget.
He said the improved route would include wider road shoulders, extra safety barriers and more passing opportunities.
"While the reinstatement work is ongoing, we are also taking the opportunity to improve this section of State Highway 1 and make it better than it was before.
"This will provide a better experience for road users and tourists who use this important route."
A new separated cycleway between Okiwi Bay and Mangamanu would also create a safer way for walkers and cyclists to experience the iconic coastline, he said.
"These improvements will provide for great journeys and enhance visitor experiences to support increased tourism and economic growth in the region."
The New Zealand Transport Agency said the work would be funded through the National Land Transport Programme and had been fast-tracked so it could be delivered alongside the earthquake reinstatement work.
The Agency's Earthquake Recovery Manager, Steve Mutton, said more workers would be taken on to ensure State Highway 1 remained on schedule to reopen by the end of this year.
"However, the route remains fragile and could be subject to short-term closures as work continues into 2018 to complete a number of improvements along the highway," he said.