Transportation experts say delays are easing as air freight systems return to normal after last week's shutdown.
UPS and FedEx both reinstated on-time delivery guarantees for packages picked up Monday.
But lengthy border inspections continue as the U.S. Customs Service continues its highest-level alert, and cross-border shippers say they still face massive tie-ups.
"It's definitely a stricter customs inspection -- they are looking very closely at everything," said Mike Dahm, district manager in Buffalo for A. N. Deringer, a customs broker. Some trucks have detoured to the Thousand Islands bridge at Alexandria Bay to bypass the traffic jam at Niagara crossings.
Meanwhile, some of the region's largest manufacturers said parts shortages they've experienced as a result of border traffic delays appear to be easing.
Last week, General Motors' engine plant in the Town of Tonawanda switched its first- and second-shift assembly workers to half-days due to parts shortages, said Dan Greene, a GM powertrain spokesman.
Operations have returned to normal this week, Greene said. As of Monday, the plant had enough parts to handle production through Tuesday.
The Tonawanda engine plant has five different product lines, unlike other GM sties. "That makes them more vulnerable (to shortages)," Greene said. The plant also receives some of its supplies from Canada, which can complicate matters when traffic tie-ups occur at the border.
Delphi Harrison Thermal Systems in Lockport, the region's largest manufacturing employer, reported some minor production disruptions caused by parts shortages. But the site wasn't forced to idle lines or workers, said Lindsey Williams, a plant spokesman. Company trucks that routinely travel across Ontario have been caught in border delays.
For all traffic, lines eased over the weekend, but Monday's volume of commercial traffic caused long waits again for trucks coming into the U.S. On Monday afternoon, the U.S. Customs Service said truck delays ran to eight hours on the Peace Bridge, 10 hours or more at the Lewiston-Queenston Bridge. Northbound trucks faced no delay entering Canada, according to Canada Customs.
"Everybody as a citizen wants to see increased vigilance," said Chip Bown, director of regulatory compliance at customs broker Tower Group International. But "as a trader, as an importer, one wants to see the goods coming in."
For non-commercial traffic, delays were about a half-hour in either direction on Monday. Travelers entering Canada should carry identification, ideally a passport or birth certificate, spokeswoman Colette Gentes-Hawn said.
Returning to the U.S. continues to be a more rigorous inspection than most travelers are used to. The "Level 1 Alert," the highest alert at the border, will continue indefinitely, a spokesman said.
"We search every vehicle and every passenger entering the U.S.," spokesman Kevin Bell said. "It's an intense, sustained anti-terrorist operation."
The border tie-ups reveal how the "just-in-time" manufacturing system that many companies favor can leave them without some supplies when there are delays in the distribution.
Manufacturers use the "just-in-time" system to avoid costs related to storing materials in their plants, instead receiving shipments shortly before they're needed.
Despite the traffic snarls, Greene, the GM spokesman, said he doesn't expect GM's business practices to change.
"Just-in-time is one of the basics of our global manufacturing system," he said. "At this time, I don't think we have any plans to change that simply because if we do that, it would cause a domino effect and we'd have to change something else, and then something else."
Ford Motor Co.'s stamping plant in Woodlawn hasn't experienced problems with parts shortages, said Meera Kumar, a Ford spokeswoman.
But the bridge tie-ups have affected companies such as Roberts-Gordon, which exports to Canada, among other many other countries. The company makes commercial and residential infared and warm air heating equipment.
Roberts-Gordon, based in Buffalo, has had some difficulty shipping to Canada, but it has sufficient inventory in that country to prevent supply problems, said Mark Dines, vice president of sales.
"A one-week disruption of supply is not really going to have an impact," Dines said.
Rigidized Metals, also based in Buffalo, expects that a shipment of tubing from a supplier near Toronto to be delayed by several days. Rigidized Metals will process the tubing before forwarding it to a customer.
The company might consider buying that item from a U.S. source to avoid similar delays in the future, said Andrew Brown, general manager of sales and marketing.
Rail shipments have also been affected by the heightened security. Norfolk Southern's daily train from Canada has seen "significant" delays, spokesman Rudy Husband said.