Traffic is building near Wellington.

There is heavy traffic on Mana Esplanade, on State Highway One, near Porirua.

There's only one lane each way north and south.

The New Zealand Transport Agency is asking people to avoid the area until the clearway opens for two lanes southbound from 3.30 this afternoon.

The heavy traffic is likely the result of many people coming back to Wellington after leaving the city for the long weekend.