American Trucking Associations’ advanced seasonally adjusted For-Hire Truck Tonnage Index fell 3% in April, following a revised gain of 0.4% during the previous month. In April, the index equaled 128.6, which was the lowest level since April 2014. The all-time high is 135.8, reached in January 2015.

Compared with April 2014, the SA index increased just 1%, which was well below the 4.2% gain in March and the smallest year-over-year gain since February 2013. Year-to-date through April, compared with the same period last year, tonnage was up 3.8%.

“Like most economic indicators, truck tonnage was soft in April,” said ATA chief economist Bob Costello. “Unless tonnage snaps back in May and June, GDP growth will likely be suppressed in the second quarter.”

Costello added that truck tonnage is off 5.3% from the high in January.

To read the full ATA report, click here.