Predicted interest rates, GDP changes and inflation are giving little reason to expect that these factors will be compensated for by a general economic upswing, Mr. Ahern added.
He advises trucking companies "to prepare for the unexpected."
Meanwhile the American Trucking Associations (ATA), in its U.S. Freight Transportation Forecast to 2024 report, predicts about 64-percent growth in freight revenue over the next 10 years.
"The trucking industry continues to dominate the freight transportation industry in terms of both tonnage and revenue," said ATA Chief Economist Bob Costello, noting the ATA projects trucking's share of tonnage will rise to 70.8 percent by 2024 from 68.5 percent in 2012.
Freight revenue is expected to grow by 63.6 percent to $1.3 trillion annually by 2024, and the trucking industry's share of those revenues is predicted to edge up to 81 percent from 80.7 percent in 2012.
Truckload volumes will grow 3.2 percent through 2018 and 1.1 percent annually from 2019 to 2024, according to the ATA. Less-than-truckload volume is predicted to climb 3.5 percent annually through 2018 and by 2.4 percent until 2024.
Conversely, the rail industry is expected to experience anemic growth for rail carloads of just 1.5 percent through 2018 and 0.4 percent from 2019 through 2024, contributing to a decline in market share to 14.2 percent from 14.8 percent in 2011, the ATA predicted.
However, intermodal rail will continue to be the fastest growing freight mode, the ATA said, growing an average of 5.1 percent a year until 2018 then slowing moderately to 4.8 percent annually through 2024.