The strong hiring at logistics-focused operations came despite slowing jobs growth in the broader U.S. economy, which added 103,000 jobs last month, and in the manufacturing and other goods-producing sectors that feed shipments into domestic and international supply chains.Trucking’s hiring blitz comes amid strong growth in U.S. freight demand. A robust U.S. economy, along with new safety regulations that require truckers to electronically track work, has pushed fleets to add drivers at a faster rate.

“Transportation providers and warehousers are doing what they have to do just to meet the demand,” said Avery Vise, an analyst at transportation research firm FTR. “They’re scrambling to fill positions that are needed just to keep the economy moving.”

Old Dominion Freight Line Inc., a less-than-truckload carrier, said its revenue accelerated from the fourth quarter to the first during the first two months of the year. In February, the firm’s shipments a day rose 13% over the same month in 2017.

“Inventories, manufacturing, housing, employment—those are all strong so it’s all fueling the freight growth that we’re seeing,” Mr. Vise said. “You can see why there’s a real urgency to play catch-up, in terms of capacity.”

Fleets are raising pay to get those drivers, and that is boosting costs for customers as the truckers pass along their higher expenses by raising shipping prices.

Cargill Inc. said this week that rising freight costs to ship packaged salt products had cut into its profits in the agriculture conglomerate’s fiscal third quarter.