At one point up to three vehicles had been traveling behind the car with their hazards on to prevent other people from overtaking the erratic driver, he said.
"They weren't letting anyone past which was quite impressive, the two cars working together, because they obviously didn't know each other.
"Initially I thought (the driver) might have been having a heart attack or something but then he kept going. He was all over the show.
"We go to the point where we could have over taken him but we thought, we don't know what he's going to do."
Police have since confirmed the driver of the car was under the influence of drugs.
Police received six complaints from motorists concerned about the driver, who was travelling northbound near Silverdale, at about 1:30pm.
The Waitemata Road Policing team were immediately sent to the area and managed to safely stop the driver.
A statement from police said the man was taken to Orewa Station where police carried out a Compulsory Impairment Test which indicated he was driving under the influence of drugs.
The man has had a blood sample taken and the results will determine police's next steps.
"The behaviour of this driver is completely unacceptable," said Senior Sergeant Tony Miller.
"Every time any one of us gets behind the wheel we have a responsibility to drive responsibly.
"It's simple. Don't drive while under the influence of alcohol or drugs. We want you here for Christmas," said Miller.
Police have extended a huge thanks to the people who reported the dangerous driver and helped them get him off the roads.
"We are grateful that we were able to get this man off our roads and prevent him from hurting innocent motorists," said Miller.
"We couldn't have done this without the help of the public."
Miller said people who chose to ring *555 and report a bad driver were doing their part to keep people safe on our roads and the outcome of this incident proves just that.