Queues are backed up to Ōtaki with significant delays of more than an hour. Photo: NZTA
State Highway 1 near Ōhau, south of Levin, will now be closed until tomorrow morning.
The road has been shut since 8am on Wednesday after the trailer of a fuel tanker rolled.
Diversions are in place at Vista Road, Muhunoa East and Bishops Road.
The road is likely to remain shut till 2am on Thursday.
Motorists are advised to avoid the area if possible, and to expect delays.