A man who fell asleep while driving and hit the car in front of him may have been trying to squeeze too much into one day, a firefighter says.

Firefighters received a callout to the intersection of Brightwell Rd and State Highway 3 at 9.45am on Sunday.

"That was a driver falling asleep ... and hitting the car in front of him and spinning out and ending up in the intersection on the side of the road," Bulls fire chief Brian Carter said.

Mr Carter said the person in front "could see the guy in his rear vision mirror coming up in the passing lane" and "veering" towards him.


"He sped up to get out of his way."

But the front driver didn't manage to get out of the way in time, and the crash happened. No one was seriously injured.

Mr Carter said the people involved might have suffered some whiplash.

He understood the man had come in from overseas and had borrowed or rented a car and was driving to Wellington at the time. He was unsure whether the man had flown into Auckland first, but thought he might have been trying to do too much in one day when he fell asleep.

The matter was being investigated, he said.