Numbers stayed that high for the rest of the year.
There were 70,000 more trips through the Northern Gateway toll road in the year ended June, 2012, than in the preceding 12 months.
Part of the reason appears to be that motorists have got used to high prices.
David Bodger, of Gull New Zealand, said: "I think people are using their cars more because petrol prices have been over $2 a litre for some time and they have got used to that price."
AA PetrolWatch spokesman Mark Stockdale agreed. AA used to say that the $2 a litre price point was when motorists would drastically change their behaviour.
Stockdale said when prices first rose beyond $2, there was a big change in behaviour. "In 2008, prices shot up from $1.50 a litre to $2.20 in six months or so. It was a huge shock and people responded quickly."
Prices then dropped back before easing up again more slowly. "Prices are now over $2 but it's been gradual, so people got used to it."
He said cars had also become more efficient, so petrol prices were not such a burden.
Campaign for Better Transport spokesman Cameron Pitches said work on the Victoria Park tunnel had made the bridge less of a bottleneck for commuters. "Drivers are now willing to take the risk."
He said people were also getting frustrated with public transport. There were reliability problems with rail, Pitches said, and even though the North Shore's busway was working well, patronage was down 2 per cent.
Auckland mother Rachel Thomas reverted to her car because public transport was unreliable. "Lost a child this week, four buses passed him by waving they were too full and he had to walk home. Imagine how impressed I was!"
Pitches said more needed to be spent on public transport infrastructure to encourage people back out of their cars.
The Government claims that NZTA is spending $890 million over three years in Auckland but Pitches' organisation discovered through an Official Information Act request that half of that spending was being financed by local government. Only $39 million was being spent on public transport infrastructure.
Stockdale said there was room for petrol prices to be cut. "Our monitoring shows that the commodity price for petrol and diesel has fallen six cents per litre in the past month. Retailers have dropped petrol by 4c and diesel by 3c."