Airlines canceled nearly 8,000 weekend flights as Hurricane Irene swept up the U.S. east coast toward New York, forcing carriers to move planes to safer areas and halting services at the busiest U.S. hub.

The disruption was part of an extraordinary preemptive effort by business and governments to limit public exposure to Irene's fury by shutting down heavily traveled transportation networks.

Subway and bus systems and passenger rail services also planned to halt service. Motorists were urged to stay off roads and key bridges would close if hurricane winds exceeded certain speeds.

As authorities from Washington to Boston prepared for ferocious winds, torrential rain and flooding, major airlines advised passengers to reconsider travel plans.

The three major New York-area airports said late on Friday they would halt domestic and overseas arrivals at noon EDT on Saturday. Departures were still planned until further notice, according to the Port Authority of New York and New Jersey.

Big airlines had already canceled much of their New York schedules into Monday.

We are laying in supplies, things like tarps to throw over computers and electronics should we shut down the terminals, and plywood so that if there is any glass damage we can move quickly to secure those areas, said Ed Martelle, a spokesman for American Airlines, a unit of AMR Corp.

The Northeast is the most congested area of U.S. air space, with John F. Kennedy and LaGuardia airports in New York and Newark in New Jersey handling nearly 100 million domestic and international passengers annually. Disruptions in the region ripple throughout the country and affect international flights.

The worst of the storm is expected to hit the mid-Atlantic region late on Saturday night and Sunday afternoon. Repositioning planes again and restarting service can take time and will lead to more cancellations and delays on Monday.

Most carriers were expected to shut down operations for about 24 hours, airlines and transportation officials said.

The online airline tracking service Flightaware.com said carriers canceled 460 flights on Friday, 2,800 on Saturday and more than 4,700 on Sunday.

* Delta Air Lines canceled 1,300 flights from Saturday through Monday. This included all operations on Sunday in New York and at Newark.

* American Airlines will halt New York-area operations from midmorning Saturday through Sunday. It has also canceled 265 flights at the three Washington-area airports on Saturday and more were planned for Sunday.

* JetBlue Airways, based at JFK, scrapped nearly 900 flights through Monday.

* United Airlines, the world's biggest airline that has eastern hubs at Washington Dulles and Newark, will cancel 2,300 flights.

* US Airways, which has a heavy East Coast presence at Washington, Philadelphia and LaGuardia, will cancel 311 flights on Saturday and another 1,000 on Sunday.

FEW ALTERNATIVES

The magnitude of the air travel disruption from Irene is more commonly seen during winter snowstorms and not the busy summer, the most lucrative period for air travel.

Helane Becker, an analyst with Dahlman Rose & Co, estimated the impact to airlines from the storm could range from $5 million if it missed the coast, to $30 million to $40 million should there be a direct hit.

Federal Aviation Authority Administrator Randy Babbitt, at the Boeing flightline in Everett, Washington, for a ceremony marking commercial certification of the Boeing Co 787 Dreamliner, said the agency had teams along the East Coast and should be up and running quickly in the event of control tower shutdowns.

The FAA said in a statement it was working to protect air traffic towers and other facilities and equipment from any storm damage. Enabling flights to resume quickly is also critical to support any disaster relief efforts.

Long Island MacArthur Airport on the Atlantic coast in New York is taking every precaution, Commissioner of Aviation Teresa Rizzuto said.

The Arca Airline stock index closed up 1.6 percent on Friday, in line with the broader market.

Airline travelers had few alternatives with Amtrak also planning to scale back Northeast rail service on Saturday and halt it completely on Sunday.

New York, Philadelphia and New Jersey rapid transit systems planned to close for the weekend.