Soon after terrorists crashed hijacked airliners into the World Trade Center, the Pentagon, and a Pennsylvania field, much of the U.S. transportation network came to a halt. The nation's airports were closed, railroad service was delayed, and crossings at the Canadian and Mexican borders were extended by hours.

Yet it quickly became clear that the U.S. transportation system was down but not out. By the time a week had passed, CSX Transportation and Norfolk Southern, the major railroads serving the Northeast, reported that they had returned to normal operations. FedEx Express, United Parcel Service, Emery Worldwide, and others had restored air service and reported operations were running normally, except for areas affected by the attacks. And the airlines, which transport significant amounts of cargo in their aircraft bellies, were rapidly restoring service. (See the accompanying story.)

But though most shippers interviewed by Logistics Management & Distribution Report and others who sent in comments by e-mail said that their shipping had largely recovered from the setbacks that followed the terrorist attacks, things were not really back to normal. Increased customs safety checks at the Canadian and Mexican borders were adding several hours to border crossings. And international air shipment delays were threatening some companies' supply chains, particularly those operating on just-in-time (JIT) schedules. The effect on shipping had been serious for many.

Many, but not all. A week after the terrorist bombings, 48.2 percent of the transportation services buyers polled online by Logistics Management & Distribution Report reported that the events had had only a slight impact on their supply chain activities, while 44.3 percent saw a significant impact. Only 7.5 percent reported no effect. Several sister magazines conducted similar polls. In response to an online survey by Purchasing magazine, 45 percent of the buyers said they had seen a dramatic impact on supply chain activities while another 30 percent reported a slight impact and 25 percent saw no effect on deliveries. Readers polled by Warehousing Management magazine reported similar results: dramatic impact, 37 percent; slight impact, 51 percent; and no impact, 12 percent. Finally, Industrial Distribution magazine found 75 percent of its readers reporting a dramatic impact, with the rest noting either a slight effect or no impact on their activities.

Though some shippers reported little or no impact from the attacks, the effects on other shippers were severe.

"We were dead in the water," says the logistics manager of a major computer manufacturer that relies on shipments from Asia. "In the current JIT environment, we were running out of products. It was very painful for us."

Her troubles may not be over. She also believes restrictions will affect company operations in the following weeks. "Delays at origin and increased security examinations will really change the process," she says. "[W]e replenish hand to mouth deliberately and on purpose. We will have to add at least a day of inventory carrying costs. That's a lot of exposure. Now, we mostly build to order. We struggled for years to get to this place; now, we have to backtrack."

Another shipper, the director of transportation for a retailer of high-value goods based in New York, also reported serious delays. "I was out of business" in the week following the attacks, he says. A week later, though, most of his domestic shipping was close to normal. International shipments were lagging, which he attributed to toughened security requirements.

Like many other international shippers, he was concerned by an initial government decision to ban cargo from the bellies of passenger aircraft. "We were looking at a real problem," he says, "especially internationally."

Another shipper reported continued delays. "Approximately 75 percent of our production, office products, and maintenance, repair, and operations (MRO) goods have been arriving on time," said Alan Tullo, purchasing manager for Serta Mattress Co. in Linden, N.J., a week after the attacks. "Normally about 90 to 95 percent of these items arrive on time."

Likewise, a U.S. logistics and supply chain manager for a French-based manufacturer reports, "Our French parent supplies many components via air freight. Delays in airfreight shipments have created downtime in our manufacturing [that] we estimate to be two weeks at this time. As a result, our deliveries to numerous customers have been negatively affected."

Other shippers were not hit as hard. The vice president of transportation for one large New York-based consumer packaged goods manufacturer says he was largely unaffected because he uses ocean transportation for much of his international import volume. However, he says he is concerned about pressure on aircargo capacity from Europe this fall. Capacity at that time of year is generally tight, he says, and any restrictions could cause problems. "If we cannot ship in passenger aircraft, everyone will suffer."

Likewise, the vice president of transportation for a major Texas-based manufacturer of MRO products reports few shipping problems following the attacks. "It hasn't had any real fierce effect," he says. But he attributes the absence of problems to a wholesale change in attitude: "People have been so understanding, so united on this issue," he says. "I may hear a complaint later, but so far, I have not heard a single complaint. It's remarkable. It's just been amazing."

Shippers relying on cross-border traffic also experienced delays—some of which were expected to continue for a long time to come.

Tom Wade, past president of the Laredo Transportation Association and distribution manager for a major electronics manufacturer, reports that the Mexican border never closed. "Trucks are still moving," he says.

Trucks may be moving, but they're moving slowly. Immediately after the terrorist attacks on the morning of Sept. 11, the U.S. Customs Service switched from normal operations to Alert Level One, which calls for "sustained, intensive anti-terrorism operation at land borders and at all points of entry." Heightened concerns about the vulnerability of trucks, ships, and the railroad system "have prompted tighter security measures that won't go away anytime soon," confirms John Holmes, supervisory special agent for Customs. The result is that at the Mexican border, where inspections of trucks carrying goods are routine, inspectors are now also inspecting empty drayage vehicles and even tractors crossing without trailers. "There's a lot more inspection and it's a lot more vigorous," says Wade. He reports that the plant where he works has had to build in about three hours of extra inventory as a result of the delays.

The added inspections have been offset to some degree by a drop in cross-border traffic attributed to the soft U.S. economy. "Bridge traffic is down 10 to 20 percent," says Wade. "If we get back to full capacity, it will be more of an issue. If the security level stays like this, delays will get longer if [customs officials] don't bring in more manpower."

Stepped-up inspections along the border with Canada, the United States' largest trading partner, extended crossing times substantially. Commercial vehicle border crossings that typically used to take about 20 minutes stretched to 15 to 20 hours in the first week after the terrorist attack. The waiting time has been reduced since then—although 8- to 9-hour waits still are occurring at some key points of entry—as customs agents search each truck and check its manifest plus the drivers' licenses, passports, or birth certificates. Wade notes that Customs has sufficient staffing along the Mexican border to carry out numerous inspections because of its drug interdiction efforts. But he suspects staffing is leaner on the Canadian border, where inspections are normally fewer in number.

Although much of the transportation system returned to some semblance of normal fairly quickly, prolonged delays in a few sectors seemed certain. And additional terrorist attacks could be devastating. One of the biggest fears is that the terrorists may not be through. "I think that it is a fact that other modes of transport could come under attack," says Jacqueline Paine, director of product distribution for America's Second Harvest, a Chicago-based company that distributes donated food to U.S. food banks. "A containership is a sitting duck and [an attack] could disrupt a major port. There's no way to check every container on a ship. Another mode at risk is rail. You've got incredible possibilities because of all the explosive chemicals that move by rail. It's very, very difficult to have good security in rail yards."

Mindful of these risks, the Department of Transportation stepped up security measures at both airports and seaports following the attacks. Transportation Secretary Norman Mineta, addressing the Senate Committee on Commerce, Science, and Transportation nine days after the attacks, said, "The odds are good that terrorists may use entirely new lines of attack. ... We will have to take precautions in transportation that we have never taken before, and we will have to do the same in virtually every aspect of American life."

By Peter Bradley, with additional reporting by Logistics Management & Distribution Report senior editors James Cooke and Toby Gooley and Purchasing magazine editor Tom Stundza.