Yellow Caution tape blocks off an entrance to a closed subway station in New York
Yellow Caution tape blocks off an entrance to a closed subway station in New York, August 27, 2011. The city that never sleeps starting shutting down at midday on Saturday with nearly all businesses except a smattering of food and liquor stores closing and public transportation coming to a halt ahead of Hurricane Irene. Reuters

U.S. airline, rail and transit systems in New York and other eastern cities initiated sweeping weekend shutdowns and slowdowns on Saturday as Hurricane Irene bore down on the region.

Tens of millions of air travelers, train passengers and subway and bus riders scrambled to adjust their routines, work commutes and vacations as transportation networks gradually scale back operations to minimize disruptions.

Coordinated transportation-related closures or slowdowns, often seen during winter storms in the Northeast, were mostly announced on Friday to give travelers enough time to adjust and ensure they stay away from Irene's fury.

New York's subway system, which carries 7 million riders daily and operates the largest fleet in the world, had never closed due to weather. The storied Staten Island Ferry was to suspend service Saturday night.

You can listen to the noise of the elevated train. That's not going to be here this afternoon, and I think that's the message that people have to start understanding, said New York Mayor Michael Bloomberg, urging residents in designated evacuation areas to heed warnings to leave.

Subways were not expected to resume until Monday.

Airlines canceled more than 9,000 flights for the weekend and another 250 on Monday, according to the online flight tracking service

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

The New York-area airports closed at noon EDT for arrivals and the last departures were expected during the evening. Those airports would then be fully closed and would reopen as post-storm conditions permitted, officials said.

The virtually empty rain- and wind-swept tarmac at Reagan National in Washington handled sparse Saturday traffic, usually the lightest day of the week. The nation's capital was not expecting a head-on hit from the storm.

Posted schedules showed flights only heading west to Detroit, Milwaukee and other cities. Reagan National, Washington Dulles, and Baltimore-Washington airports all planned to stay open through the storm even though airlines were halting service.

Airports have backup generators that are usually reserved for maintaining power at air traffic towers and for public safety. But expectations were that Washington airports would be active again Sunday afternoon.

If it goes through and is all over by late (Sunday) morning or early afternoon, things should get back on track, said Tara Hamilton, spokeswoman for Reagan National and Washington Dulles.

As at New York airports, airlines moved jetliners to safer areas like Chicago and other Midwest airports.

We are not keeping any aircraft in Irene's path, said Andrea Huguely, a spokeswoman for American Airlines, a unit of AMR Corp.

Other carriers heavily affected include US Airways, Delta Air Lines, and United Airlines.

The Federal Aviation Administration (FAA) said it was working to protect air traffic towers and other facilities and equipment from any storm damage. Despite the shutdown of regular service, some FAA controllers would remain at East Coast airports to handle any emergency, rescue or military flights.

More than 1 million people evacuated the New Jersey shore areas via roads over a 24-hour period, the state's governor, Chris Christie, said.

Christie sharply urged those remaining at Jersey Shore resorts on Friday to get the hell off the beach and leave the region to avoid the storm.

Maryland planned to close the 180-foot-high Bay Bridge, which spans the Chesapeake Bay and links the Maryland and Delaware shore with the Washington region, later on Saturday. Virginia closed the 20-mile Chesapeake Bay Bridge Tunnel further south.

Authorities also planned speed and lane restrictions on the Delaware Memorial Bridge, a major north-south span on Interstate 95, and could order it closed if conditions warranted. New York authorities said they could close the George Washington Bridge, depending on Irene's winds. Other New York City suspension bridges could also close.

New York harbor was emptied of ships.

Airline travelers had few alternatives with Amtrak also scaling back Northeast rail service on Saturday and planning to shut it down on Sunday.

Freight rail operator CSX curtailed local service in coastal North Carolina and Virginia and would resume operations as conditions allow.

CSX was inspecting tracks along the mid-Atlantic region. Locomotives, rail cars and crossing gates were secured ahead of the storm.