State Highway 2 travels over the Remutaka range between Upper Hutt and Wairarapa Photo: CC Deano87
It is slow-going for motorists driving over the Remutaka Hill following a two-vehicle crash near the summit on the Wairarapa side.
Waka Kotahi said the southbound lane of State Highway 2 had been blocked, but the northbound lane remained open.
Emergency services and contractors were at the scene.
Drivers were being told to take care going through the crash scene and to expect delays.
Earlier the transport agency warned Wellington drivers to expect congestion as Easter holiday-makers returned home, with SH1 through Kāpiti and SH2 over the Remutakas expected to be busy.
They asked travellers to check their journey planner for updated road conditions.
Meanwhile, no deaths have been reported on the roads so far over the Easter holiday period, but several people have been seriously or critically injured in crashes.
Five died during Easter last year, and seven the year. No deaths were recorded in 2020 when the country was in Covid lockdown.
The Easter holiday period ends at 6am tomorrow morning.