Spot truckload freight volume had the strongest April on record, despite slipping 6.8% lower, a common seasonal trend, according to newly released figures from the DAT North American Freight Index.

This measure of activity on DAT Solutions’ network of load boards also showed compared to the same month in 2017, freight availability rose 32%. Flatbeds contributed disproportionately to the volume increase, with a 59% boost compared to a year ago.

Flatbed freight rates set another record in April, at an average of $2.65 per mile, including fuel surcharge, a 12 cents increase over the previous record in March. Flatbed rates were a full 58 cents higher in April than in the previous year.

Average van rates rose to $2.16 per mile, a 2 cents increase compared to March. Rates for refrigerated cargo were up 3 cents to an average of $2.43 per mile month-over-month. Rates gained 49 cents per mile for both trailer types, compared to April 2017.

Rates continued to rise sharply through the first week in May, as weather improved in the Northeast and Midwest, and produce harvests added to pressure on truck capacity in the Southern band of states, especially Georgia and Florida, according to DAT Industry analyst Mark Montague.

“May and June are typically peak season for agriculture and construction, and retail freight appears to be expanding, as well,” he said. “Seasonal demand should keep rates high at least through the end of the second quarter.

The report follows figures DAT released a couple of days earlier that showed average spot freight rates increased in all three major categories during the first week of May.