Wellingtonians have jumped at the opportunity to ride Transmission Gully

The 1.25 billion dollar motorway north of Wellington has been open for a week after years of delays and budget blowouts.

It's reportedly made a huge difference coming in and out of the Wellington region.

Porirua mayor Anita Baker says it's significantly reduced traffic along the old State Highway 1 route.

She says it's much quieter in Pukerua Bay and Paremata.

Baker says Pauatahanui and Whitby have picked up a bit of traffic -- but that it's still flowing very well.