The Government has committed to rebuilding State Highway 1 to Kaikoura - at a cost of more than $1 billion.
Transport Minister Simon Bridges said SH1 and the rail corridor along the coastal route to the north and south of Kaikoura would be rebuilt in about 12 months.
"Since the day of the earthquake, restoring access to Kaikoura has been our number one priority. Agreeing to restore the coastal route demonstrates our ongoing commitment to getting this region back on its feet as quickly as possible," Bridges said.
"To provide certainty, the Crown will fund the work required. Exact costs are still being determined, but the current estimate is between $1.4 billion and $2 billion.
"In addition, emergency legislation passed through Parliament last week will cut through red tape, and ensure repairs to the existing route can be accelerated."
Bridges said an Order in Council was being prepared that would accelerate the rebuilding on SH1.
"The precise work required to repair the route is still under investigation and it will be a very complex job. However, the Government is confident that limited access via the coastal route can be restored in about 12 months.
"Rebuilding a stronger, more resilient coastal route will give Kaikoura residents the security of a second connection to the rest of the South Island."
KiwiRail chief executive Peter Reidy said the organisation would work to restore freight services on the main northern line from Picton to Christchurch as soon as possible, and work would begin immediately.
"KiwiRail will look for temporary fixes in some parts of the line to allow for restricted, freight-only rail services in the first instance while the permanent road and rail lines are completed.
"This will ease pressure on SH7 and SH63, as the roads have struggled under the influx of freight trucks during the peak period."