ANZ's Truckometer is flagging a slowdown in economic growth, though not a sharp one.
The heavy traffic index, which reflects movements of trucks and milk tankers on roads selected because they have historically had a close correlation with economic activity at the time, rose 1.8 per cent last month, seasonally adjusted, following a 1.2 per cent drop in August.
The light traffic index, reflecting movements of cars and vans on roads chosen because they have provided a pointer to activity six months ahead, rose 0.7 per cent on top of a 0.4 per cent rise in August.
"The two indexes correctly picked slower but still solid quarterly gross domestic product growth in the June quarter," ANZ economist Sharon Zollner said.
But the heavy traffic index had lost considerable momentum, she said, which suggested that when the statisticians report September quarter GDP just before Christmas it "may tend towards the mediocre". By contrast the light traffic index suggested annual GDP growth would steam ahead.
