Class 8 truck orders are projected to fall once again in March, down as much as 12% compared to February, according to the latest numbers from ACT Research and FTR.

At around 16,000 orders for the month, this is the lowest level of demand for Class 8 trucks since September 2012, according to FTR.

Compared with last March, orders are down nearly 40% as freight conditions cause an uncertain economic environment for fleets that would otherwise be looking to replace older vehicles.

“Freight has slowed due to the manufacturing recession, so they have sufficient trucks to meet current demand,” said Don Ake, vice president of commercial vehicles at FTR. “Some fleets are also delaying replacing older units until conditions improve.”

By contrast, the medium-duty Class 5-7 market is projected to see improvement in March as the segment continues to grow. ACT Research expects 21,700 medium-duty truck orders in March, an improvement of 4% year-over-year. A decent jobs market, rising incomes, and improved housing activity are propping up medium-duty demand, according to ACT.

“Medium-duty and heavy-duty demand, as mirrored by new order activity, remain on divergent paths that are tracking their niches in the broader economy,” said Kenny Vieth, ACT’s president and senior analyst. “Order strength through Q1 continues a period of meaningfully stronger orders, which began last September.”