Since the industry was deregulated 25 years ago, one constant for economists is that truck freight tonnage has moved in parallel with the country's manufacturing output numbers. When output went up, so did tonnage by about the same percentage.

For the last two years, though, manufacturing has grown at the same rate as the country's overall gross domestic product (GDP) or even exceeded it, but truck freight has actually declined. And that has the economists puzzled. Are they witnessing a temporary anomaly, or is there a structural change under way in North America's freight traffic? The answer to that question has serious implications for truck fleets of all types, not just for-hire freight haulers.

There are a few theories about what's behind the disconnect. One is that because the economic indicator is measured in dollars, it may be hiding a gradual shift in manufacturing from heavy, but lower value, goods to lighter, but more expensive, ones. For example, the aerospace industry is doing well now while housing is in a slump. If you look at dollar value for the mass and weight of truck shipments for those two industries, aerospace economic activity generates its highest values from engineering, while housing consumes far more truck services hauling heavy, but relatively low-value, goods.

The numbers, especially when viewed in light of decent GDP growth over the past few years, may also mask a change in the types of goods being consumed these days. Think growing sales of flat-screen TVs and other electronics, while a home building slump means lower sales of wood products, steel, flooring and other heavier constructions materials.

The decoupling of manufacturing and truck tonnage growth could also be the result of a weak dollar, according to other economists. While the weak dollar boosts U.S. exports, and therefore the overall economic numbers, exports change the transportation pattern. Trucks carry the new exports to ports, but the final legs of their transportation are occurring offshore.

High energy costs might be another contributor. Here, the thinking goes, major shippers are working hard to lower their freight bills (which include significant fuel surcharges) by taking weight and cube out of their freight with better logistics and even reengineered packaging.

Some make a reasonable argument that the change may reflect private fleets gaining some freight share from the for-hire carriers. And, of course, the tonnage numbers don't reflect any activity on the service side of trucking. Shifts in inventory controls and holiday buying patterns could also account for the change.

While this might just be an anomaly with little long-term meaning, there is also good chance that it indicates some fundamental shift in the truck freight markets. Overall, those markets are expected to be strong — actually robust — over the next decade. But if the freight types, destinations or movement patterns change significantly as the market strengthens, will you be ready to participate in that growth?

The economists' forecasts are far from clear, but they're beginning to think that something is going on. No matter what type of fleet you operate, it might be time to look for early signs of those structural changes in your own fleet.


E-mail: jmele@fleetowner.com

Web site: fleetowner.com