NEW YORK - The Transportation Security Administration says passengers have been moving "quite smoothly" through security checkpoints at U.S. airports as the Thanksgiving holiday comes to a close.

At Sea-Tac Airport Sunday, most travelers were able to check in fairly quickly, and most of the flights were on time with just a handful of delays. TSA wait times hovered around 15 minutes.

More: FlightAware: Live tracking maps, flight status, and airport delays

Sea-Tac officials say around 140,227 passengers will have come through the airport on Sunday. Another 135,665 passengers are expected on Monday.

One place you might notice delays is in the line of traffic to get to the curbside in pickup areas.

TSA spokeswoman Lisa Farbstein says about 2.5 million passengers are expected to be screened Sunday, the last day of the Thanksgiving holiday weekend. That's about 500,000 more than a typical weekday.

Lines at Atlanta's Hartsfield-Jackson International Airport were long but moving smoothly.

At New York's Kennedy Airport, lines were short and flowed quickly. Amtrak in New York City also was running normally.

In Cleveland, a spokeswoman for Hopkins International Airport says it's been "extremely busy" during certain times of the day.

In Washington, a spokesman says long security lines at Ronald Reagan Washington National Airport subsided by the afternoon.