The supply of Class 8 trucks has continued to rise faster than demand, according to the ACT For-Hire Trucking Index.

The capacity index rose faster than the freight index in December, causing the largest imbalance between supply and demand since 2012. It is the fourth consecutive month that supply has risen faster than demand and the 10th time in 2015.

“We have to go back to the second half of 2012 to find a comparable period of imbalance – a period marked by anemic economic growth and strong U.S. Class 8 retail sales,” said Steve Tam, ACT’s vice president, commercial vehicle sector.

Because of the excess supply, truck purchasing is expected to be reduced until the imbalance is corrected.

“Truckers have caught on to the fact that there is excess freight hauling capacity in the market and have started curtailing their purchases accordingly,” said Tam. “Sales are likely to continue on a downward trajectory until the oversupply of trucks is consumed.”