After months of dismal surface freight demand, for-hire truck tonnage surged in April, climbing 7.4 percent from March and rising 7.7 percent year over year, the American Trucking Associations (ATA) announced Tuesday. But was the freight business really that good?

“I do not think the fundamentals underlying truck tonnage are as strong as April’s figure would indicate,” the ATA’s own chief economist, Bob Costello, said in a statement. The Cass Freight Shipments Index shows US trucking and intermodal volumes dropping in April, as well as the previous four months.

It may be, as at other times the ATA tonnage index spiked unexpectedly, that we’re seeing a correction from a previous period in which shipping was weaker than expected. “Some of the gain was a catch-up effect” after a particularly weak February and March, Costello said.

Similar events occurred in 2016, when the ATA tonnage index jumped 7.2 percent in February, before dropping 4.5 percent in March, and then rose 5.7 percent in August, following a 2.1 percent decline in July.

When numbers spike at a time when they’re expected to be lower, seasonal adjustment can magnify the increase. Easter’s late date this year, April 21, may have affected that adjustment, as well as the underlying tonnage numbers, amplifying a freight surge.

In the past four years, the ATA index has dropped from March to April, and that’s another reason a mild non-adjusted volume increase would appear bigger after a seasonal adjustment.

At 7.3 percent, the year-over-year gain for ATA’s non-seasonally adjusted tonnage index for April was strong, too. Sequentially, however, the non-adjusted index only rose 1 percent. That still shows there’s life yet in the domestic freight market, which is expanding, albeit slowly.

It’s also important to note that higher tonnage doesn’t necessarily equate to increased shipments. ATA’s for-hire truck tonnage figures may include heavier freight, including raw materials that feed manufacturing and construction, that can skew comparisons.

Even a smaller gain in tonnage, however, is a good start to a second quarter that is likely to see a drop in US imports due to the escalating US trade war with China. “This may signal that any fears of a looming freight recession may have been overblown,” Costello said.