The Christchurch to Picton route south of Kaikoura will be closed between 10pm tonight and 6.30 tomorrow morning while 16 temporary rockfall-retainer containers are moved.
Operations manager Tresca Forrester says it's the best time of day to do the necessary work - with the lowest volume of traffic about.
"We're heading towards winter so we are trying to get as much done as winter almost comes with challenging weather conditions for our crews on the ground. The work's progressing really well."
There'll be further night closures in a month to remove the final temporary rockfall protector containers and up to 300-concrete blocks.
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