What a difference a year can make.

Just ahead of the busy summer travel season, lines for security screenings are shorter at U.S. airports.

Although airlines and airports are urging fliers to get to the airport two hours early for domestic flights and three hours for international trips, the wait times of 60 minutes or longer to get through Transportation Security Administration screening in Philadelphia and other cities last spring have not been repeated.

TSA staffing is up, more  dogs have been deployed, and contractors hired by airlines are assisting TSA officers in getting passengers through screening checkpoints.

"Due to measures put in place last year, it's smooth sailing so far," said TSA spokesman Michael England.

Last May, Congress shifted $34 million to the TSA to hire more screeners, which today total about 45,000 nationwide. In addition to more security officers, part-time workers were converted to full-time, and TSA is paying overtime, if needed.

Airlines, including American, hired contractors to help manage the security lines and assist TSA with "nonessential" security functions such as distributing and retrieving bins and keeping passengers moving through security lines.

In Philadelphia, employees of airline subcontractors, McGinn Security and PrimeFlight Aviation, have been trained by the TSA to help steer passengers, remind them to empty pockets, throw out water bottles, and remove their shoes. "Just reminding people does speed up the lines," England said.

In one week, March 14 to March 20 last year, 6,800 passengers on American missed their flights in Philadelphia, Los Angeles, Miami, Atlanta, and Dallas-Fort Worth because of long TSA lines.

The reasons for longer wait times included more people traveling, fewer airport screeners because of congressional budget cuts, and tightened airport security measures after terror attacks in Paris and Brussels and the downing of a chartered airliner over Egypt's Sinai Peninsula in October 2015.

"It's very different this year," said American spokesman Ross Feinstein. "We have not seen a repeat of what we saw last spring break."

"I can confirm that the lines are not long," said Victoria Lupica, American spokeswoman in Philadelphia. "The reason you can sense that it's spring break is because the parking garages are full. But when you come into the airport, everything is normal."

Again this spring, air travel is projected to be at a record high. Airlines for America, the industry trade group, expects 145 million passengers — nearly 2.4 million a day — to fly globally on U.S. airlines between March 1 and April 30, an increase of 4 percent over last spring's 140 million fliers.

The airline group said Monday that airlines are adding 110,000 seats on planes to accommodate 89,000 additional daily passengers expected to fly during this time.

"As we approach the spring and summer travel season, you all remember painfully that we had a meltdown," said Sharon Pinkerton, senior vice president at Airlines for America, on a conference call. "Wait times were up to three and four hours in some airports."

To address the crisis, TSA has set up an incident command center, she said.

Airlines have daily contact with TSA, which tracks daily screening operations, and airport staffing to address problems that arise, including deploying additional personnel and canine teams. TSA has added 2,000 staff since last spring, and can transfer part-time employees into full-time jobs, Pinkerton said.

To help ease travel, TSA said this month that it was working with airlines and airports to open more automated screening lanes, allowing passengers to move more quickly through checkpoints. Automated screening lanes are now open at Newark Liberty, Chicago O'Hare, and Los Angeles International airports, the agency said.

American Airlines said it will soon test new screening technology with the TSA at the Phoenix Sky Harbor airport. The computed tomography (CT) scan, which is currently used for checked luggage, will be tested on carry-on bags. And if it's successful, TSA may expand it to airports nationwide.

About 9.5 million fliers — up from 6 million in 2015 — have enrolled in "trusted traveler" programs designed to expedite screening and wait times. Global Entry is a U.S. Customs and Border Protection program that allows preapproved travelers, for a $100 fee, faster Customs clearance upon arrival in the United States. TSA PreCheck, which costs $85 for five years, gives vetted passengers faster screening — shoes, belts and light jackets stay on, laptops and liquids stay in bags.