The largest publicly owned U.S. trucking companies increased their combined revenue 11.3 percent year-over-year in the fourth quarter, as increased U.S. industrial output, containerized imports, consumer confidence and lower fuel costs put more freight in tractor-trailers.

The 21 public motor carriers tracked by JOC.com reported total revenue of $10.7 billion, making the fourth quarter the third straight period when the group’s combined sales surpassed $10 billion. For the full year, group revenue jumped 10.9 percent to $41.5 billion.

The 11.3 percent annualized fourth-quarter growth rate compares with a 5.1 percent increase in the fourth quarter of 2013. Likewise, the full-year revenue increase for the trucking group in 2013 was a more tepid 3.3 percent, compared with revitalized 10.9 percent in 2014.

The fourth-quarter results point to a healthier carrier base, with more sustainable profits. Despite rising trucking rates, that’s good news for U.S. shippers, exporters and importers, that depend on those carriers to provide a significant portion of over-the-road capacity. Trucking companies increasingly are able to invest profits back into their businesses.

The trucking companies’ performance closely reflects broad improvement in the U.S. economy, now in its sixth year of recovery. Real U.S. gross domestic product increased 2.4 percent in 2014, compared with 2.2 percent in 2013, according to the U.S. Bureau of Economic Analysis. In 2013, U.S. GDP growth is widely expected to hit 3 percent.

Personal consumption, exports, private inventory investment, state and local government spending and residential fixed investment all boosted real GDP in 2014, the BEA said. Imports increased as well, creating more freight, although cutting into GDP growth.

U.S. GDP has risen more than 3.5 percent in four of the six quarters since the third quarter of 2013, climbing 4.6 percent in the 2014 second quarter on a sequential basis, 5 percent in the third quarter and 2.6 percent in the fourth quarter, according to the latest BEA estimate. Year-over-year, U.S. GDP increased 2.6, 2.7 and 2.5 percent in the last three quarters.

Even in the weather-beaten first quarter, when GDP dropped 2.1 percent from the previous quarter and expanded only 1.9 percent year-over-year, the public trucking companies increased combined revenue 9 percent, a higher rate than in the previous eight quarters.

A look back at the annualized revenue growth rate for the publicly owned trucking group over the past 12 quarters shows how the carriers weathered and then emerged from the “soft patch” that slowed the recovery in 2012 and 2013. The revenue growth rate slowed from 9.3 percent at the start of 2012 to 1.7 percent in the first quarter of 2013 and only climbed past 5.1 percent in 2014.

Profitability was strong for most of the truckload and less-than-truckload carriers at the end of 2014. None of the 20 carriers that report operating or net income reported a loss, and 17 increased profits from the 2013 fourth quarter. Those that did so on average increased profit 66 percent. YRC Freight, USA Truck and J.B. Hunt Transport Services’ truckload division all recovered from year-ago losses.

“We’re continually managing our yield, managing our network,” USA Truck President and CEO John Simone said in an interview Feb. 11. “That’s where we’re seeing improvements.”

Contact William B. Cassidy at wcassidy@joc.com and follow him on Twitter: @wbcassidy_joc