Ten days after Hurricane Katrina shut down a major nexus of American commerce, many choked shipping lanes have been reopened, gasoline pipelines restored to service, and goods rerouted as businesses try to limit the economic fallout of the storm.

But key parts of the Gulf Coast's transportation systems, communications and energy production remain out of service for the foreseeable future. And yesterday, the Congressional Budget Office estimated that the hurricane may slow U.S. economic growth by up to 1 percentage point over the rest of the year.

Katrina's damage to the physical infrastructure that keeps the regional economy going remains immense. Some 57 percent less oil than normal was pumped from the Gulf yesterday, and natural gas output is down 40 percent. Major highways in and around New Orleans are still closed, as is a 100-mile stretch of railroad. The Port of New Orleans remains shut down, and other nearby ports are working at limited capacity. More than 1 million telephone lines and about 30 percent of cell phone towers in the affected region remain out of service. And yesterday, more than 503,000 business and residential customers in Louisiana were still without electricity.

However, many businesses are finding ways around these problems, underscoring the resilience and nimbleness of the U.S. economy's modern supply and distribution networks.

Pilot Air Freight Corp., a Pennsylvania company that does shipping and logistics for companies worldwide, has routed trucks around the affected areas. It even managed to get trucks into New Orleans on Saturday to ship a load of industrial materials to Brussels, despite not having access to its shipping facility at the city's airport.

"What surprised me in this disaster is how well the system adapts," said Richard Phillips Jr., vice chairman of Pilot. "It's a little bit like how if you take one connection out of the Internet, it works around the problem and information still gets through."

In the boot-heel region of Missouri, the southernmost tip of the state, the corn harvest has begun. But prices are down, and, with the Louisiana ports shipping only 10 percent as much grain overseas as normal, farmers worry they will have to leave their crops to rot in the fields, said Kelly Smith, director of marketing and commodities of the Missouri Farm Bureau.

Downriver, barge operators are more sanguine.

"Cargo is moving," said Bob Wooten, a vice president and co-owner of Weber Marine Inc., which services shippers and tows barges on the Mississippi River 65 miles upstream of New Orleans. He said that his company has already salvaged a few barges that washed ashore in the hurricane and that nearby grain elevators are operating or will soon. His own company is working at 80 percent of capacity, largely because many of his employees are unreachable, presumably evacuated.

"It's been a lot of work, but I'm really proud of our people," Wooten said. "But I hope I never see another can of beanie weenies in my life. I've been living off the things for the last two weeks."

And Oreck Direct LLC, a vacuum cleaner company with headquarters in New Orleans and a manufacturing plant near Gulfport, Miss., is set to resume production after executives gathered in temporary offices in Dallas and delivered 75 mobile homes, food, water, and generators to their plant in Mississippi. Suppliers agreed to stockpile parts, and United Parcel Service Inc. took over distribution tasks that normally would be handled in-house.

"It's pretty amazing that a business can be virtually shut down and be back up and running almost fully in 10 days," said chief executive Tom Oreck.

Businesses such as Oreck, Weber Marine, and Pilot have kept operations going by bypassing the region's conventional transportation and communications networks. Government officials say that efforts to repair those networks, which might allow companies to get back to working at full speed, are proceeding with mixed progress.

Commercial airline service could begin as early as today at Gulfport-Biloxi and will likely resume next week at Louis Armstrong New Orleans International Airport, Department of Transportation officials said yesterday. The New Orleans airport has been closed to commercial air traffic since it lost power during the hurricane and has been operating as a makeshift hospital.

In Louisiana, several highways remain closed to the public. State officials said it could be a long time before a major bridge that crosses Lake Ponchartrain is restored, providing access to northwest New Orleans. State officials are inspecting 90 moveable bridges in the area to prioritize repairs. Many other sections of the highways that feed into New Orleans remain closed, and it could be weeks or months before they are reopened.

Railroad company CSX Corp. said its 100-mile stretch of track from Pascagoula, Miss., to New Orleans has been closed, with 30 miles severely damaged. The company declined to estimate how long it would take to restore the tracks and is routing traffic around the area. One of its tracks crosses a 9,000-foot bridge in Mississippi that was left to its pilings as the hurricane swept away most of the bridge itself. "We're looking at it as a long-term recovery," said CSX spokesman Gary Sease.

Louisiana officials yesterday began dealing with cell phone systems in Baton Rouge that are overloaded with traffic from evacuees who have reached the state's capital. "It's choked," Louisiana Public Service Commissioner James M. "Jimmy" Field said of the cellular network. "We are trying to work out something to make sure emergency calls can get through."

Just 8 percent of the 215,000 customers in New Orleans had power yesterday, according to state and power company reports.

Oil and natural gas production is slowly returning. While oil production was down 90 percent on Sept. 1, it was down only 57 percent lower than normal yesterday. And natural gas was off 40 percent, compared with 79 percent on Sept. 1.

Even for the companies that successfully navigated all the downed infrastructure, the use of generators, satellite phones and rerouted shipments may exact new costs. "Businesses are going to be able to get around all these disruptions, but it won't be cheap," said Peter Morici, an economist at the University of Maryland business school.

Washington Post staff writers Peter Behr, Justin Blum and Arshad Mohammed contributed to this report.

The Mississippi River is the cheapest route for shipping many crops and other commodities destined for overseas markets. The United States exports a quarter of its grain; of that, more than half departs from ports hit by Katrina.