The big Thanksgiving getaway went into full swing Wednesday with drivers delighted by the lowest November gas prices in years and many airline passengers undaunted by terrorism fears and long lines at security checkpoints.

At the White House, President Barack Obama said there is no "specific and credible" intelligence indicating a plot against the U.S. and assured anxious Americans: "While the threat of terrorism is a troubling reality of our age, we are both equipped to prevent attacks and we are resilient in the face of those who would try to do us harm."

"And that's something we can all be thankful for," he added as one of the biggest travel periods of the year got under way.

Nearly 47 million Americans are expected to take a car, plane, bus or train at least 50 miles from home over the long holiday weekend, according to AAA. That's the most travelers since 2007, a rise attributed to an improving economy and the cheapest gasoline for this time of year since 2008.

Pat Flynt had the recent terror attacks in Africa and Paris on his mind as he waited to get through a checkpoint at the Atlanta airport for his flight to visit a sick uncle in Baltimore.

"Hopefully there are no issues. That's my main concern," he said. "But with what's been going on recently, I don't care how long they take. I just want to be safe."

Joyce Landeck was about four hours into her nearly 1,100-mile Indianapolis-to-Denver drive when she made a pit stop in Missouri to find gas for $1.62 a gallon.

"Oh, yeah," she said while clutching the leash of her travel partner, a Doberman named Murphy Brown. "It's really, really nice when it costs 30 bucks to fill the tank."

Erin Goff makes the trip from Lake Panasoffkee, Florida, to Wichita, Kansas, nearly every year and occasionally flies but decided "I wanted no part of that" this time for fear of a terrorist attack.

"That was out of the question," she said. So she found herself taking a break from the 1,350-mile drive at a convenience store in the Oklahoma City suburb of Moore, where she marveled at the price of gas: "It's going to cost about half of what it cost a year ago or two years ago."

In the West, drivers faced fresh snowfall in California's Sierra Nevada and rain in the San Francisco Bay Area. Motorists in Montana and Wyoming were warned of icy roads after wintry storms moved through. Travelers heading out on Thanksgiving Day could see 8 inches of snow in the Denver area.

Anyone heading to a major airport should factor in 50 extra minutes on the road, according to the traffic data company INRIX. And then there's the time spent going through security.

In Atlanta, traveler Fatima Boyd said Transportation Security Administration officers were thorough but friendly.

"I think they're making sure that everybody has safe travels and in great hands and nothing crazy goes on during the holidays," she said. "So that's a plus."