Norfolk Southern Corp. announced that profits increased 12% in the first quarter as a result of strong rebounds in coal and intermodal business compared with early 2016.

Old Dominion Freight Line Inc. reported profits rose 9.1% in the first quarter, a positive start for the major less-than-truckload companies scheduled to report earnings by May 5.

Swift Transportation reported profits plunged 84% in the first quarter compared with 2016 as truckload carriers suffered from continued excess capacity and lower contract prices than they had hoped for this year.

Ryder System Inc. reported profits fell 32% in the first quarter compared with 2016 after a drop in demand to rent trucks and an overall weak used truck sales market continued into 2017.

Rail freight companies began the earnings season with mixed results as profits rose 1.7% at CSX Corp. but plunged 20% at Canadian Pacific Railway Ltd. in the first quarter compared with the same period a year ago.

Heartland Express Inc. reported profits fell 2.3% after a sharp decline in revenue due to the soft freight environment and poor weather in the western United States.

Kansas City Southern reported profits rose 36% in the first quarter, although the gains were lowered to a 12% increase after applying the exchange rate between the Mexican peso and the U.S. dollar.

Truck tonnage rose 0.7% last month compared with March 2016, although the American Trucking Associations’ chief economist said that late winter storms hurt the index compared with this past February.