Manufacturers, retailers and seafood distributors have increasingly turned to air cargo planes to transport products — a more expensive, but faster and more reliable alternative to longhaul trucks, trains and ocean vessels often bogged down by current supply chain problems.

Real economic activity in the U.S. is slowing sharply. This is showing up in lower demand for new trucks and autos, and a tailing off in freight volumes, leaving transport stocks facing more downside.

Union Pacific Corp. plans to limit customer-owned railcars on its network beginning next week to ease traffic jams that have gummed up the supply chain.

Strong consumer demand, continued supply chain bottlenecks and tight carrier capacity sent air, ground and ocean transportation rates soaring to historic levels in 2021 as shippers leaned on third-party logistics providers to bolster inventories and avoid product stockouts.

The past two years have been difficult ones for shippers to move their freight. But times like these are when logistics providers can most clearly demonstrate the value they bring to their business partners.

The head of the U.S.’s second-busiest container seaport said he has seen no letup in import volumes, though there may be some slowing in coming months as high inflation and growing services spending threaten to temper consumer demand for goods.

The Logistics Managers’ Index, a measure of U.S. supply chain pressures, rose to a record.

The wait times for semiconductor deliveries rose slightly in March, reaching a new high, after lockdowns in China and an earthquake in Japan further hampered supply.

The latest warning sign for U.S. stocks is emerging from a corner of the market that investors closely watch to get a read on the state of the economy and the health of American consumers: Transportation shares.

WASHINGTON — Recent passage in the U.S. Senate of comprehensive legislation aimed at boosting domestic manufacturing of semiconductors is helping to set in motion formal negotiations with House lawmakers.