NZ Transport Agency Waka Kotahi (NZTA) said the road is closed to all traffic, with no local detours available.
“Travel between Marlborough and Canterbury is affected today following a serious crash on State Highway 1 south of Blenheim this morning.
“The highway is closed to all traffic following a car‑versus‑car crash near Cloudy Bay Drive – no local road detours are available.”
The Serious Crash Unit has been informed.
Motorists are advised to expect delays or avoid travel if possible.
A spokesperson from nearby Riverlands-based business Tinto Containers said there’s a long line of traffic being turned away by emergency services.
“By the looks of it they’re [drivers] not being allowed to continue south on State Highway 1. It’s blocked off just before the turn off to Redwood Pass Rd.”
The spokesperson said it wasn’t uncommon to see emergency services scream past the area.