A truck has rolled on the Wellington Urban Motorway, State Highway 1.
No one was injured but the southbound lanes have been blocked.
Diversions are in place via The Terrace off-ramp.
A Fire Service spokesman said a small tanker carrying bitumen rolled on a section of the motorway near Clifton Terrace.
The truck rolled onto its side but the driver was not hurt, he said.
Meanwhile, a Wellington City Council truck slipped down a bank and against a garage in Tawa this morning.
Council spokesman Clayton Anderson said the truck, which had a woodchipper on the back, was being used to prune trees away from wires on Woodstock Terrace when the accident happened sometime between 9 and 10am.
"It slid down a bank and it's come to a rest against a garage and it's damaged the garage's roof," Anderson said.
"Nobody was injured and, yeah, basically we don't quite know how it happened but we're investigating it."
A crane is expected to come in about midday to lift the truck out.
A police spokeswoman said police had been notified about the incident, as the road needed to be closed while the truck was removed.