The economy is still struggling to gain momentum, largely because of uncertain global conditions and a high New Zealand dollar, according to the latest ANZ Truckometer indexes.
The Truckometer analyses data from the movements of light and heavy vehicles, using the results to predict economic activity.
Heavy vehicle traffic tends to be an indicator of current economic activity, while flow for cars indicates future growth or decline.
The report for December shows the heavy traffic index fell 5.4% and light traffic dropped 1.3%.
"This indicator flagged weakness in GDP during the third quarter of the year and while we can see semblances of a pickup, the underlying picture remains one of softness across the economy," the report says.
It says there is no clear underlying trend, suggesting a stagnant economy.
"The economy has soft momentum and is yet to offer substantive signs of recoil and improvement.
"The headwinds the economy is facing in the form of an uncertain global scene, high levels of external indebtedness, the high New Zealand dollar and a soft labour market make anaemic growth quite understandable."
However, the report suggests the lacklustre economic performance could also be because the expected benefits of the Christchurch rebuild and a booming housing market have not flowed into the broader economy.
"Neither yet seem to be delivering the critical mass to alter the broader economic picture.
"Various sentiment surveys offer hope but timely real-time data such as our Truckometer flags caution."