Longer daylight hours and warm temperatures are the "best time" for resurfacing roads, the New Zealand Transport Agency says, because the conditions help new seal stick to the road surface.
It comes as resealing work last week, just north of Tuamarina, caused queues up to 3km long.
The work - part of New Zealand Transport Agency Waka Kotahi's (NZTA) summer highway maintenance programme - finished on Friday.
An NZTA spokesperson said the warmer spring and summer months were the best time for resurfacing.
"Warm weather helps ensure the new seal becomes strong and long lasting," the spokesperson said.
"Bitumen (asphalt) and emulsion are liquids when they are hot and hard when cold.
"They can crack in cold weather, return to a liquid state in high temperatures, and wet road conditions during sealing will affect the bond between the bitumen and the road, leading to chip seal failures.
"During the peak summer months, it is a balance to programme as much work as we can before schools return, while the roads are quieter, whilst also minimising the effect on people's holiday travel."
The Tuamarina reseal was separate to work taking place at a water-damaged section of State Highway 1, near Picton, which was expected to be finished in October.
Large cracks had started to form on the highway, near the Picton elevation, following a build-up of underground water pressure.
A northbound slow lane had been closed for the repairs.
Meanwhile, night closures were planned for State Highway 6 between Hira and Rai Valley from 11 February to 1 March. The closure would not happen on Friday and Saturday.
NZTA top of the south system manager Rob Service said parts of the highway needed to be resurfaced before winter to ensure the highway was safe and in "tip-top shape".
"We have deliberately timed the work to happen at night and outside the busy holiday period," Service said.
"It means we affect as few road users as possible."
It was the first major work on the Whangamoa Saddle since a seven-week closure for flood repairs in 2022, Service said.
"We realise road closures are disruptive, but they're actually the best option," he said.
The road would open once at 12.30am each night to let traffic through.
The summer maintenance programme included multiple sites across the top of the south, including SH1 Weld Pass.
Work on the installation of two new roundabouts on SH6, west of Blenheim, had also commenced and was expected to take at least until mid-May.
- LDR is local body journalism co-funded by RNZ and NZ On Air.