A baby narrowly avoided being born on the side of a gridlocked Auckland motorway on Thursday, with his panicked parents getting a surprise police escort to hospital.

Constable Shaw (no first name provided) was driving on the Northern Motorway on Thursday afternoon, heading back to Orewa station after finishing his shift, when he saw a vehicle parked in the emergency stopping lane.

"I went and spoke to the driver to make sure everything was okay," he said in a statement released by police today. "There was a woman in the backseat, clearly in labour."

The distressed first-time parents, Shradda and Gaurav Patil, had missed the turnoff to North Shore Hospital.

"Unfortunately the motorway was just jam-packed," said Gaurav. "I started sweating and I called 111. The next minute, Constable Shaw stopped for us."

After escorting their vehicle a couple of kilometres, Shaw realised the "ridiculous" traffic meant there was a good chance the baby would arrive before they could get to the birthing unit - so he pulled them over and told them to hop in, turning on the lights and siren.

"I walked them up to the suite and left. It was quite cool - a once in a career opportunity," said Shaw.

Baby Aarav, completely unaware of the commotion he had created, did not end up arriving until 7.30am Friday.

Gaurav said he did not get much time to thank Shaw for his efforts.

"I cannot express how relieved we were to see him. The way Constable Shaw helped us, it was just amazing."