ANZ says its Truckometer is still pointing to strong momentum in the economy despite dipping last month.
The heavy traffic index, which reflects flow of trucks and milk tankers on 11 roads closely correlated with economic activity, fell 1.5 per cent after rising 0.5 per cent in October.
The light traffic index, a pointer to activity six months ahead, fell 1.1 per cent after rising 1.8 per cent in October.
Both indexes gave an early heads-up that gross domestic product in the September quarter was likely to be strong, said ANZ economist Sharon Zollner, who designed the Truckometer.
"Following a strong quarter there is always the risk of a recoil in the December quarter. Factors such as the timing of dairy exports will throw the quarterly [GDP] numbers around. We prefer to focus on the overriding story of a strong second half of the year."