Fire crews and a specialist hazardous materials unit were dealing with the fuel spill that closed Transmission Gully on Wednesday. Photo: Supplied / Fire and Emergency NZ
Transmission Gully is closed in both directions between Pāutahanui and Paekākāriki due to a crash causing a significant fuel spill.
A specialist hazardous materials unit, eight fire engines and a tanker were at the scene on State Highway 1 north of Wellington where a fuel tanker and another vehicle crashed.
The spill closed the highway about 6am, and Waka Kotahi said it would not reopen until the afternoon.
Northbound motorists were advised to use State Highways 58 and 59 to get back on to SH1.
Southbound travellers should use the detour via SH59.
Traffic congestion had eased by late morning but drivers should still expect delays on SH59, Waka Kotahi said.
Fire crews set up a dam and isolated the fuel leaking from the tanker, Fire and Emergency said.
Group manager Gareth Hughes said the amount of fuel lost from the tanker was not yet known, but fire crews had worked hard to stop it reaching an environmentally sensitive area.
A second fuel tanker was being brought to the site to decant the remaining fuel.
"Until that is complete, there is still a risk of an explosion so the road is remaining closed," Hughes said.
An environmental protection officer had been sent to the scene.