A serious crash this afternoon involving a bus and a car is keeping SH1 at Clarence closed this afternoon into the evening.
The next update on the situation will be at 7pm tonight.
The Police Serious Crash Unit is investigating.
The crash occurred after 1pm.
Electronic boards are advertising the closure at Blenheim, Waipara, Picton and north of Kaikōura. These will be updated once a single lane is restored later this evening.
People should anticipate a much slower journey along SH1 even after it reopens, advises Waka Kotahi, NZ Transport Agency.
The other way to get between Blenheim and Christchurch
The alternative route between Blenheim and Christchurch is via SH63, the Wairau Valley and St Arnaud through to the Lewis Pass/Waipara (SH7).