Trailer orders in May rose to the highest level for that month since 1998, continuing the strong growth trend that has been building this year, ACT Research reported.

Trailer buyers placed 22,308 net orders with U.S. manufacturers last month, a 52.2% increase compared with 14,655 in May 2013.

ACT analyst Frank Maly said constrained freight capacity is contributing to replacement purchases and fleet expansion.

“Things are still tight, and there’s still the need for equipment out there,” he said.

Year-to-date, orders are tracking 45.2% ahead of last year’s pace. Trailer makers booked a total of 133,665 new orders in the first five months of 2014, up from 92,050 in the same timeframe last year.

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