ORLANDO, Fla. — Shippers attending Nasstrac’s annual meeting here stressed the importance of reliability, service and relationships, even as cost remains the top concern.

As tank fleets replace their long-lived trailers, they are turning to vehicles that take advantage of several innovations in recent years to increase strength, reduce weight, resist corrosion and better protect products, according to carriers and manufacturers.

Universal Truckload Services’ first-quarter income fell from a year ago on a change in tax status, the truckload carrier said.

Schneider National Bulk Carriers said it has launched a bulk intermodal transportation service utilizing a new 40-foot tank container that can be used on trucks or trains to haul liquid bulk chemicals across the United States.

Norfolk Southern Corp. and Canadian Pacific reported their first-quarter profit increased but Canadian National said its profit declined.

Forward Air Corp. said its first-quarter net income rose from a year ago, and that its revenue also improved.

Canadian transportation firm TransForce Inc. said its first-quarter net income dropped, on persistent softness in the economy.

Kansas City Southern’s first-quarter income rose to $104.2 million, or 94 cents a share, from $75.3 million, or 68 cents, a year ago.