Transportation congestion is a mushrooming problem, costing the American economy billions of dollars annually, but there is an alternative to some of this gridlock. It is an option that is being largely overlooked here but not in many other countries around the world. It is the inland waterways system. The Interstates, often six or eight lanes wide, are jammed much of the time, and truck traffic keeps growing. Until September's terrorist attacks, there had been too many passengers and planes trying to use airports that lack the runways, terminals and gates to handle the traffic, particularly at peak-travel times. Now, just-imposed security procedures are adding hours to airport delays. And bad weather in almost any part of the United States is still the domino that can topple the rest of the air traffic system. Railways face a different sort of congestion. Problems arise in moving containers in and out of busy coastal ports because of lengthy access lines through densely populated areas. Congestion also crops up at the Mexican border, at railroad switch yards, and with seasonal traffic flows. And recent railway mergers have led to massive traffic backups.

High water, low water, and ice conditions cause temporary disruptions in river shipping, but the river system generally functions rather efficiently, moving approximately 1.1 billion tons of traffic annually. Outmoded navigation locks are the chief cause of congestion on the inland navigation system, and as modernization of the inland waterways continues, bottlenecks are increasingly the exception, rather than the rule.So how did the U.S. transportation system become so choked?

l There is a lack of consensus on system capacity. Theoretically, every mode could move a lot more planes, trucks, cars, trains and barges than it does. But in the real world in which we live, traffic doesn't flow evenly over a 24-hour period. So capacity may be constrained only at peak periods, but it's enough to inflict severe economic losses.

l There's a lack of consensus on transportation needs. According to one estimate, airports will have to spend $100 billion over the next 10 years on improvements (exclusive of security upgrades). The Federal Highway Administration estimates highway needs of $83.4 billion over 20 years. On the waterways, the backlog of authorized navigation construction is approximately $9 billion. The comparable cost of navigation needs is far less than that required by the other modes.

l There is a lack of appreciation of infrastructure. Sadly, America has let its infrastructure slowly disintegrate. In an August speech, Sen. Harry M. Reid, D-Nev., called for a 'Marshall Plan' for infrastructure renewal. Roads, bridges and water systems are in a state of disrepair, he said, calling for a fresh commitment of resources.

At a time when everyone is more environmentally sensitive, waterways are a sensible alternative. A typical 15-barge tow moves as much cargo as 225 railcars or 870 large semi-trucks, gliding almost silently through the water. Towboats require less fuel per ton-mile of commerce and generate far less air pollution than trucks or even trains. They are a safe mode of transportation -- barge channels are located many blocks if not miles away from downtown districts and residential areas. Consider the benefits of cleaner air, safer streets, less noise and vibration if some of the bulk commodities now transported on trucks or trains were shifted to barges.

U.S. waterways have a lot of capacity to handle more intercity freight shipments. America's waterways are convenient and often strategically located and have the capacity to move more traffic efficiently and cost-effectively. The waterways are a mode in waiting, a mode willing and able to do their part to solve America's transportation crisis.

Our trading partners in Europe, Asia and South America are already emphasizing their water transportation facilities. As a matter of national policy, some European countries offer shippers incentives to switch traffic from other modes to the waterways. Japan recently inaugurated a 'modal shift' program to take freight off its overloaded highway system.

Waterways must be a truly integral component of tomorrow's intermodal freight transportation system. The inland waterway system is basically in place; only adequate maintenance, rehabilitation and replacement projects are needed. It makes good sense to look to barges and ships for help in taking some of the mounting pressure off the other bulk-transportation systems.

Harry N. Cook is president of the National Waterways

Conference Inc. He can be e-mailed at hcook@waterways.org. These comments are excerpted from his speech to the group's annual meeting in Louisville, Ky., on Sept. 20.