Commercial trailer demand dropped in May compared to the previous month’s orders as part of a seasonal slowdown, according to the latest projection from ACT Research.

ACT projects a total 14,250 trailers ordered for the month, down 16% from the 16,911 ordered units in April. Compared to May 2015, orders are down nearly 12% from 16,175 units.

“Although commercial trailer orders have been progressing at a better pace than Class 8 volumes, the expected seasonal slowdown in order placement has begun,” said Frank Maly, ACT’s director of commercial vehicle transportation analysis and research.

A bad freight environment with poor truckload and less-than-truckload pricing may cause trailer orders to sync up more with the lower Class 8 tractor demand, according to analysts at Stifel Transportation & Logistics Research Group.

One aspect helping the trailer market was OEMs opening ordering earlier than normal. Some manufacturers have already booked orders for 2017 delivery as early as March, instead of August or September as the OEMs have typically done in the past.