While exploring reasons for the current slowdown, economists who study the big picture have discovered the impact of traffic tie-ups on commerce. Putting a price tag on snarled traffic is a new exercise, but some rudimentary statistics are emerging.

Figures from the Texas Transportation Institute (TTI) in College Station, an arm of Texas A&M, suggest that in 1999, the most recent year studied, it cost $50 to $70 an hour to operate a commercial vehicle. Every minute stuck in traffic snatches at least a dollar from the average fleet's bottom line. TTI estimates that the total cost of congestion in the U.S. is $72 billion, up from $66 billion in 1996. If commercial vehicles make up about 5% of total traffic, $3.3 billion annually would be lost — mainly in fuel, wages and idle truck time.

During recent budget hearings, Sec. of Transportation Norman Mineta said that his department is committed to battling congestion on highways and at U.S.-Mexico border crossings. Earlier this year, DOT introduced a computer tool for public sector freight planners to help them identify current and future bottlenecks in the nation's transportation system.

In addition, officials of the two-year-old Office of Freight Management have declared war on traffic congestion and will hold a summit next year focusing on easing traffic jams. Legislatures in many states have specifically tagged congestion as an impediment to their state's economic well-being.

As a culture, we tend to believe that throwing enough money at a problem can fix it. The sad truth about traffic congestion is that money doesn't always work.

“There is no solution,” says David Schrank, a TTI researcher and co-author of its congestion study. “The only thing you can do is chip away at the problem a little at a time with small improvements,” he says. “A 1% change here and a 1% change there, and it adds up.”

A more pessimistic view comes from Anthony Downs, senior fellow at the Brookings Institution, who testified before Congress that nothing short of Americans moving closer to work will solve the congestion problem. “There is no way to prevent traffic congestion from intensifying even more in the future. This is a problem without a solution — at least no solution the American people will accept.”

To be sure, carriers have their own ways of dealing with congestion. Many drivers take out-of-the-way routes such as I-81 instead of the more direct but urban I-95 on the East Coast. Others can be seen waiting out the rush hour at rest areas. Companies like Dell Computer have decided to dispatch drivers at night to escape the daytime traffic.

But these are quick fixes that won't endure as traffic becomes worse over the next decade.

Building more roads is difficult because communities usually fight their construction. Mass transit doesn't work either because work patterns change more quickly than public transit construction. Intelligent vehicle systems and other technology fixes such as PrePass help, but not enough. So what's a fleet manager to do?

The best immediate solutions are to spur local governments to make many small changes. “The best we can do is push back the rush hour a little more, shorten it by a few minutes,” says Shrank. Sometimes, simply changing merging patterns with different striping helps. The Twin Cities tested the effect of ramp metering by turning it off for several months. Traffic got worse and officials learned that ramp metering helps manage the rush hour's peak, but can never get rid of it altogether. In Virginia, white sedans with the words “motorist assistance” are dispatched to help stranded motorists because they draw fewer rubberneckers than police cars.

Many traffic researchers are pinning their hopes on eliminating bottlenecks, believing these choke points are the major component of congestion.

Opponents say that fixing bottlenecks will only encourage more cars to use a route — the concept of “induced travel” — and we're no better off than before.