Several sections of highway on the West Coast will be closed overnight for three weeks while safety markings are repainted.
State Highway 7 from Springs Junction to Reefton will be the first - closing tonight at 10pm.
It will close for seven nights, but will open between midnight and 1am to clear any traffic.
From next Monday, it will be the turn of various sections of State Highway 6 between Haast Pass and Franz Josef to close overnight.
Waka Kotahi says the closures are weather-dependent, but are expected to finish by 21 October.