A fallen tree on State Highway 1 that caused several hours' worth of headaches for travellers heading north from Auckland this morning has now been cleared. 

However, Waka Kotahi NZ Transport Agency says the congestion hasn't gotten much better. 

"Due to holiday traffic, motorists are advised to expect northbound delays between Silverdale and Wellsford," the agency warned around 9.30am. "Allow extra time for your journey." 

Crews were sent to the site of the large fallen tree, about 1 kilometre south of Puhoi, at around 6.30am. The tree blocked northbound lanes but was causing delays in both directions. 

By 8am, most of the backup was confined to northbound lanes. 

"Contractors are on site and stop/go traffic management is in place to remove the tree," the agency reported at the time. 

It had caused delays of 10 to 15 minutes for northbound traffic between Silverdale and Warkworth.