Heavy traffic index dips after July rise

ANZ's heavy traffic index fell 1.2 per cent last month after rising 2.5 per cent in July.

"The trend in the index appears to be flattening out, suggesting lower growth rates ahead," said ANZ economist Sharon Zollner, who designed the indicator.

The heavy traffic index reflects flows of vehicles weighing more than 3.5 tonnes (primarily trucks) on 11 roads around New Zealand chosen because of their close historical fit to gross domestic product growth at the same time.

Meanwhile, the companion light traffic index, which reflects flows of cars and vans on 10 selected roads around the country and which gives a pointer to GDP growth six months ahead, lifted 0.4 per cent last month after a flat July.

The light traffic index had been predicting a re-acceleration of growth towards the end of the year, Zollner said, but that was before global dairy prices started falling like a stone.

"We must therefore now take that acceleration story with something of a grain of salt, given events are evolving quickly. But it is nonetheless encouraging that the light traffic index suggests a solid baseline of momentum, which will help the economy negotiate headwinds."