The economy is robust. The United States unemployment rate is at all-time lows. Pacific Rim nations are resuming their consumption of North American-made goods and products.

Ocean carriers are building increasingly larger container vessels for the Pacific trades and preparing to transport even denser cargo loads. The consensus of the Asia Pacific Economic Cooperation (APEC) Transportation Working Group is for rapidly expanding production output among Asian nations and the United States. Usually reliable estimates suggest a growth rate exceeding 15 percent annually.Each of these factors paints a glowing picture of prosperity and future economic growth - or do they?

Stripped of its potential complexities, freight transportation in nearly each shipment method includes the use of a heavy-duty tractor and trailer to physically move cargo from one point to another. This requires both mechanical equipment and a human being to drive.

While there are sufficient sources of heavy-duty trucks and trailers, the same cannot be said for truck drivers. In fact, judging from the collective experience of the trucking industry in the past few years, the applicant pool for these jobs has all but evaporated.

While companies continue to lose and gain drivers, new hires are, for the most part, veterans from other companies. It is not mere happenstance that some major truckload carriers have taken to purchasing other carriers. Clearly, many of these deals have as their primary focus the acquisition of drivers, not market share.

Although trucking schools continue to produce new drivers, the number of such graduates does not equal the number of workers leaving or retiring from the business. Hence, the driver pool is static at best.

It is becoming clear that trucking can barely keep up with current demand levels during peak shipping periods, let alone the projected growth.

Nothing in the current environment suggests that a solution to this growing problem has been conceived. Prevailing opinion in the trucking industry holds that, since deregulation, freight rates have fallen, which, in turn, has reduced (or at least substantially limited) a driver's rate of pay.

Moreover, the climate in which drivers ply their trade has worsened due to a combination of factors, including just-in-time delivery, reduction of inventory levels, use of temporary warehouse personnel and the presence of international carriers in the U.S. marketplace. These exacerbate most carriers' ability to recruit and retain competent and safe drivers.

Assuming for the sake of argument that the above view accurately depicts today's supply-and-demand marketplace, what are the implications?

In general, rates will inevitably rise as demand exceeds capacity, resulting in better-paying and/or more efficient freight moving while less-desirable freight sites.

The broader implications are more problematic. Using APEC's estimates, the ports of Los Angeles and Long Beach produce in excess of 100,000 truckloads per week and will grow to approximately 250,000 truckloads per week by 2010. These ports' internal estimates, though more conservative, suggest a doubling of growth by 2020 or 200,000 truckloads per week.

Under either estimate, given the apparent inelasticity of capacity in this market and unless productivity is substantially increased, these additional shipments will not move by traditional methods. What then?

On-dock rail is theoretically capable of handling some of this additional demand, but can only absorb a relatively small percentage of the growth due to physical constraints and labor-related restrictions.

Moreover, as we observed during the Union Pacific Railroad crisis last year, each of our Western railroads reached nearly full capacity during the peak periods. Hence, even with on-dock rail origination, there will still be capacity restrictions on the main lines and in the yards.

Additional parallel trackage and locomotive power could increase rail capacity, but such expansion is historically disfavored by capital markets and thus improbable. Rob Krebs of the Burlington Northern Santa Fe added significant capacity last year only to be rewarded by a decrease in share values.

However, even if railroads could add significant capacity, it would quite probably be too little to forestall a crisis. With no disrespect to railroads, they transport only a relatively small amount of consumer goods being shipped.

Trucking is the primary mode of cargo transport in the $1.3 trillion United States market, accounting for approximately 75 percent of all cargo revenue. Since trucks require drivers, the shortage is a distinct roadblock to continued economic expansion.

If my conjecture is accurate, the question becomes whether we will recognize and take action to deal with the impending crisis before it damages our economy.

If there is sufficient sentiment to be proactive, there is real potential for improving driver productivity and thereby expanding capacity. Such reforms will take the joint action of governments, shippers, receivers and carriers as well as the application of developing technologies. I'll explore some ideas in that regard in a future article.