Waka Kotahi NZ Transport Agency has apologised to road users following a major traffic jam on State Highway 8, between Beaumont and Raes Junction yesterday.
A spokeswoman said traffic movements were slowed down at the Beaumont bridge because of a traffic light sequencing fault, which took about an hour to resolve.
Witnesses said a queue of traffic was backed up about 6km, from the bridge to nearly Raes Junction.
Some said they had been waiting for up to an hour to get across the bridge on State Highway 8.