NEW YORK (CBSNewYork/AP) — Holiday travelers are seeing a greater police presence in the wake of the terrorist attacks in Paris.

The Port Authority has stationed more officers at its airports, bus terminals, train stations and Hudson River crossings.

PHOTOS: NYC Beefs Up Security

The heightened concern about terror threats is on the minds of many traveling on what is one of the busiest travel days of the year.

“You have to be crazy not to be concerned,” Clem Loew, who was flying from LaGuardia Airport to Chicago, told CBS2’s Janelle Burrell.

The State Department issued a worldwide travel alert for Americans. The alert, which is to be in effect until Feb. 24, said current information suggests that militants with the Islamic State, al-Qaeda, Boko Haram and other terrorist groups continue to plan attacks in multiple regions.

President Barack Obama urged the public on Tuesday to be vigilant, but not to give in to fear.

“That’s how terrorists win,” he said. “We cannot give them the victory of changing how we go about living our lives.”

Obama reiterated on Wednesday that there is no specific, credible terror threat to the U.S. homeland.

Nevertheless, Transportation Security Administration and airport officials are urging people to give themselves plenty of extra time as they travel over the holiday weekend.

Before dawn, many passengers at LaGuardia Airport, which is expected to see as many as 300,000 travelers coming and going between now and Sunday, had to wait in long lines at TSA security checkpoints. But by mid-morning, most were breezing through the American Airlines terminal, Burrell reported.

“I was expecting crowds,” said Marcy Blank, of Bayside, Queens. “I got my boarding pass in two seconds.”

Some passengers said they are very confident in the level of security.

“I feel safe,” said Kenneth Brown, of Wakefield, in the Bronx. “I always feel safe.”

Daniel Klein and his family said they noticed more police and bomb-sniffing dogs than usual.

“No concern at all,” the Upper West Side resident said. “Business as usual.”

Flyers largely said they were aware of the threats and alert, but not afraid, WCBS 880’s Mike Xirinachs reported.

“What can you do?” said one man who was headed to Chicago. “You’ve got to just keep living your life.”

“We can’t allow what’s going on to stop us from enjoying our lives,” another woman agreed.

“On one hand, it makes me feel a little more secure, noting heightened alertness and awareness,” traveler Sonya Robinson told CBS2’s Jennifer McLogan. “But at the same time, if people are determined to do bad things, they will do bad things.”

1010 WINS’ Glenn Schuck talked to one man who arrived three hours early for his flight to Florida.

The precautions “are something that has to be done,” the man said.

As part of the alert, federal officials are telling people to be especially cautious in large crowds.

Meanwhile on the rails, Amtrak has reported many of its routes are sold out and it is adding more trains.

“A lot of trains out there. This is our Super Bowl. This is the busiest travel time of the year,” said Amtrak spokesman Craig Schulz.

“They say they are checking IDs on the train. So hopefully they’ll really be doing that. Hopefully that’s enough,” said traveler Carol Striano.

In fact, one child riding Amtrak from D.C. to Penn Station told McLogan that as each rail passenger boarded at Union Station in D.C., security officials snapped photos of faces of every traveler, and no one seemed to mind.

The increase in security is also evident at the end of the Macy’s Thanksgiving Day Parade route in Midtown.

“They’re everywhere,” Teri Butler, of the Lower East Side, said of the police presence. “I like that. I love that. That’s very important. We need that here in the city.”

For the parade itself, police officials said there will be hundreds of extra uniformed police officers and traffic agents as well as mobile cameras, helicopters, mounted units, specially trained dogs, radiation detectors and other security measures.

“This year, for the first time, our force will be supplemented by approximately 200 freshly trained armed critical response command cops, working along with our police officers from the Strategic Response Group,” said NYPD Chief of Department James O’Neill. “There will be a lot of police presence — things the public will see, and of course, things the public will not see.”

Police Commissioner Bill Bratton said the NYPD is doing everything to make people safe.

“Some of those officers will be equipped with the long guns, as we refer to them; the rifles. We’ll have additional Hercules teams – those are the heavily armed entities that will be around the area of the parade route,” Bratton said. “But I think the police presence will heighten the sense of security.”

Bratton stressed that there are no specific or credible threats against the city.

Meanwhile, those driving to their Thanksgiving destinations are enjoying lower gas prices. Robert Sinclair with AAA Northeast told WCBS 880’s Paul Murnane that regular unleaded fuel in New York is averaging $2.45 a gallon, 86 cents cheaper than a year ago.

He added that this is expected to be the busiest getaway since 2007 and AAA is bracing for more than 7,000 service calls over the holiday weekend in New York City, Long Island and Westchester County.

At the Vince Lombardi rest area along I-95 in Ridgefield, New Jersey, 1010 WINS’ John Montone talked to a man who was driving his Porsche from Miami to Brewster, in Putnam County.

“I left at 1 p.m. yesterday.”

He said he hadn’t gotten any sleep.

“Nothing,” he said. “Just bombing through energy drinks.”

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