The Sunday after Thanksgiving is traditionally the busiest travel day of the year, and this year about 2.7 million people will return home on that day. This comes on the heels of a Worlwide Travel Alert issued by the U.S. State Department, and many travelers are concerned about safety. Watch Peter Greenberg’s report for CBS News and keep reading to find out how travel security could change.

1. With the increased security, what will travelers expect at the airports and train stations when they return home this holiday weekend?

If they’re flying home from a U.S. airport, lines at TSA checkpoints will be crowded on Sunday. The best time to return will be Friday or Saturday. But lines will take longer to process, because at certain airports TSA inspectors have been instructed to ramp up behavioral profiling. That means engaging some passengers in a conversation and asking questions that can’t be answered by a simple yes or no.

Checked baggage will be under more scrutiny, so if you’re flying with wrapped presents, don’t be surprised if they are opened by TSA inspectors. The DHS might deem a number of flights high risk, so don’t be surprised if positive bag matching is implemented more widely—that is, no one can check bags on a flight and then not get on the flight and have those bags fly. Under that protocol, expect to see some flight delays as bags of passengers not on the flight are removed before the plane pushes back from the gate.

There will be an increased show of police force at train stations like Penn Station in New York and Washington D.C.’s Union Station. Passengers may be asked to have their bags inspected on a random basis.

2. What tips do you have to beat traffic and long lines?

This year, a lot of folks got smarter about their Thanksgiving travel plans and didn’t wait to leave town on Wednesday. But that only meant lines weren’t as long on Wednesday.

But this Sunday is another problem altogether. That’s when everything will be jammed. The only good news—advance weather forecasts are telling us there will be minimum storm activity over the weekend.

Here’s a good tip at the airport security checkpoints: When you see multiple lines at security, don’t just opt for the shortest. Check to see how many TSA officers are looking at the security monitor for the carry-on bags passing through the conveyor belts—if there’s one officer, no matter how long the line, pick that one. If there are two, it means they are training one of the officers and just about every bag will be stopped on that conveyor belt.

3. Will security concerns affect travel prices this upcoming holiday season?

Domestically, not much movement is expected, with the exception of Christmas. This is a generally slow travel season and prices tend to be lower during this time. However, overseas is a different story.

Consider this: Not surprisingly, flight bookings to Paris collapsed in the week following the terrorist attacks, according to the latest figures from travel data analyst, ForwardKeys (this company monitors future travel patterns by analyzing 14 million reservation transactions each day) and net bookings—which takes into account both daily bookings and cancellations—were down 101 percent at the same period last year.

New reservations to Paris are slow to return. Here’s how it lays out: Although the number of cancellations now appears to be leveling off, there has been a noticeable dip the day before the start of the international climate talks, COP21, in Paris beginning on November 30.

Accumulated bookings for the Christmas holiday period—compared with last year—plateaued immediately after the November 13 attacks. Overall, the number of cancellations from November 14 through 21 increased 21 percent compared with the same period last year, although they have now returned to normal levels.

The number of new bookings remains down 27 percent, compared with the same dates last year. The picture for Christmas continues to look bleak with the number of bookings for travel during this period now down 13 percent, compared with the same period last year. Before the terror attacks, they were just 2 percent behind.

Also, not surprisngly, bookings to Belgium have essentially collapsed.

Flight bookings to Brussels have collapsed in the wake of the recent attacks in Paris and the lockdown in Brussels, as police search for more suspects. ForwardKeys reports that net bookings show a drop of 159 percent since the beginning of the weekend, when the lockdown was announced. To put this in perspective—if net bookings are down 100 percent, that indicates that no net bookings were made. Down by 159 percent means that in addition to no bookings made, there were cancellations equal to 59 percent of the number of bookings made on the equivalent day last year.

4. How have the recent threats affected the price of  flights to Europe?

Before the November 13 attacks in Paris, a round trip ticket in economy class from New York to Paris ran about $1400. On Thursday it was as low as $597.

5. If you had booked a trip to Paris, can you postpone or cancel it without a fee?

Keep in mind that the Worldwide Travel Alert is not a travel ban. The warning only urges U.S. citizens to exercise increased caution. Because of that, airlines are not waiving ticket change or cancellation penalty fees.

For more information about travel safety, check out:

• The Travel Detective Blog: What A Worldwide Travel Alert Means For You
• NTSB Most Wanted List Highlights Ignored Travel Safety Issues
• What Are the Safest Airlines in the World?

By Peter Greenberg for PeterGreenberg.com