ANZ senior economist said the monthly data was volatile, hit by Covid, supply disruptions and shortages. Photo:
Traffic movements are sending mixed signals on the direction the economy is travelling.
The ANZ Truckometer's Light Traffic Index lifted another 1.9 percent in September, while the Heavy Traffic Index eased 3.3 percent, following a strong jump in August.
ANZ senior economist Miles Workman said the monthly data was volatile, hit by Covid, supply disruptions and shortages.
"The Heavy and Light Traffic Indexes went in different directions in the month of September," he said.
The light traffic index, which included cars, motorbikes and vans, had surged, which was considered a positive indicator of consumers' willingness to spend.
"The Heavy Traffic Index tends to provide a better steer on production GDP," he said, adding there was more uncertainty around the latest data.
"Truck movements have recently likely reflected labour shortages as well as Covid waves coming through."
The Heavy Traffic Index rose 1.6 percent over the quarter and suggested the economy continued to expand at a solid pace.
Workman said the data indicated the economy could be growing faster than the bank's forecast for 0.4 percent quarter on quarter third quarter GDP growth.
"But just like the traffic data, the GDP data has its fair share of Covid-related volatility, making the predictability value in indicators, such as heavy traffic just that little more uncertain," Workman said.