A decline in orders of Class 5-7 trucks in May points to "some moderate slowing" in a truck market that has shown strength since late 2013, according to ACT Research.

Medium-duty net orders totaled 17,865 units in May, which showed a decline over April and May of 2015. However, the final numbers were somewhat higher than the initial projection of 17,100 units.

May results in the overall medium-duty market were directionally consistent with historical expectations, said Steve Tam, ACT's vice president for the commercial vehicle sector.

"While there is solace in the year-to-date performance, some moderate slowing is likely," he said. "The pullback in orders appears to be the culmination of efforts to populate the distribution channel with new product, likely to result in a subsequent slowing of production and decumulation of inventory."