NEW YORK (ABC News) - As Hurricane Sandy nears the eastern third of the country, hundreds of flights and trains have been canceled, while New York City's rapid transit system, the largest in the world, is scheduled to be shut down tonight.
Gov. Andrew Cuomo said the subway, bus and railroad services would be suspended beginning at 7 p.m. EST. He said he hoped the closure would keep New York-area residents from being "up and about."
"[Trains are] not intended to be submerged, and we want people to stay at home," he said.
Approximately 15 million people in New York City, its suburbs, New Jersey and Connecticut rely on the transit system.
Amtrak is canceling parts of its rail service between New York and Washington D.C. on Sunday, while New Jersey Gov. Chris Christie warned residents to be prepared for a potential shutdown of the New Jersey Transit system on Monday.
Sunday also brought hundreds of flight cancelations, with more scheduled for Monday as airlines prepare for the "perfect storm."
More than 3,000 flights have been canceled for Sunday and Monday so far, according to data from FlightAware.
More than 700 U.S. flights have been canceled for Sunday and 2,500 have been canceled for Monday. That number is expected to rise.
Every airline has issued a flexible travel policy that allows customers to make changes to their reservations with no penalty. Check your individual carrier's homepage for details.
United Airlines, with a hub in Newark, N.J., has been the most aggressive so far in getting ahead of the storm. According to FlightAware, the airline has cancelled more than 300 flights today.
The airline told ABCNews the majority of those flights are scheduled for Sunday evening.
"United is working to operate a normal schedule to the east coast through the late afternoon hours. We have selectively canceled flights beginning this evening through tomorrow to many airports in the northeast and mid-Atlantic states," Rahsaan Johnson, an airline spokesperson, said in an email.
"Travelers who are booked on a flight to or from a city in the storm's path this evening or Monday should assume it is delayed or canceled and should verify flight status at united.com. Customers whose flights are canceled or delayed more than two hours are eligible for a refund."
Some hotels are offering discounts to travelers stranded by the storm. Kimpton hotels in New York City and Boston offer 20 percent off rates. Use promotion code SANDY.
In Washington, D.C., the Ritz-Carlton, Georgetown offers a special nightly rate of $229 including free parking and Wi-Fi.
Hurricane Sandy is expected to bring life-threatening storm surge flooding to the Mid-Atlantic coast and could wreak havoc for days across 800 miles of the United States, impacting tens of millions of people in the eastern third of the country.
Sandy will meet up with cold front coming from the northwest and a high pressure system from Greenland, fueling it with enough energy to make it more powerful than the "Perfect Storm," some meteorologists say.
"This storm that is going to be impacting the mid-Atlantic and parts of the Northeast...is going to be destructive, historic, and unfortunately life threatening," AccuWeather's Bernie Rayno said.