Auckland's regional fuel tax is being credited with helping to shift Aucklanders out of their cars and onto public transport.
A detailed analysis of trip data by the council's chief economist shows bus and train use in outer-lying areas grew by three to four times that in central suburbs, after the 11.5 cent a litre tax came in last July.
"That's really strong evidence," said the council's chief economist David Norman, after sifting through 450,000 rows of figures.
Norman said patronage in August and September 2018, was up 26.5 per cent, and 9 per cent in the outer-most local board areas of Franklin in the south and Rodney in the north, compared with a year earlier.
That compared with growth of just 1-2 per cent in the more central suburbs.
And that's after correcting for other factors like increased frequency. And its fairly obvious: if you change prices, then people change their behaviour. But the problem is going to be making sure the people in those outer suburbs have access to decent public transport, so they can switch, rather than simply being forced to pay more with no alternative.
As for why this is a good thing, in addition to reducing congestion, it will also help reduce greenhouse gas emissions. Which is why we need to make such measures a key part of our climate change response. Give every major city a regional fuel tax to fund its public transport, and watch New Zealand get cleaner.