FORT WORTH, Texas - In a quest to speed up the boarding process, American Airlines is letting passengers board sooner if they travel lightly.

The airline said Thursday that people carrying just a personal item that fits under the seat - no rolling suitcases - will be allowed to board before most other passengers.

American said that the change will allow flights to take off sooner, helping the airline improve its on-time performance.

Airline officials say boarding times have increased in the last few years. The airlines have created this problem by cutting back flights, which makes planes more crowded, and also charging fees for checking baggage, which encourages passengers to haul their luggage on board.

The result can be sharp-elbowed competition for scarce bin space that leads to short tempers among passengers and flight attendants.

American tested the new boarding procedure at seven airports earlier this year and began applying it to all flights Thursday. Passengers carrying just a personal item such as a purse, backpack or computer bag that fits under the seat will board right after Group 1 premium passengers and before groups 2, 3 and 4.

The airline said that it will let passengers check a carry-on bag at the gate at no charge. That means savvy travelers will be able to move up in the boarding order and avoid checked-bag fees - $25 for the first bag, $35 for a second on flights within the U.S. - although they'll have to retrieve their bag at baggage claim after they land.

If it works as designed, light travelers will be seated quickly. Fewer people will be stuck behind the inevitable guy who takes too long to hoist his rolling bag into an overhead bin and position it to his liking.

Kevin Doeksen, director of customer planning for American, said the change will cut boarding time by about two minutes per flight, "which doesn't sound like much, but it adds up throughout the day."

If the change results in fewer big bags being rolled on the plane, it could reduce the number of flights on which the overhead bins fill up. When the bins are stuffed, gate agents or flight attendants must ask passengers in the last boarding group to surrender their bag for gate-checking - an awkward situation all around.

Competition for bin space has also made travel more stressful. Passengers in the last boarding groups often creep forward and jockey for position to be the first in their group on the plane.

"They're anxious because they've got a big roll-aboard (bag with wheels) and they're worried about having no space in the bin," Doeksen said.

Travel experts think American's idea can speed up boarding if enough passengers leave their rolling bags behind.

Chris Lopinto, president of ExpertFlyer.com, said the key could be American's offer to check bags at the gate for free. It won't appeal to business travelers on a schedule, who don't dare check a bag - ever.

"But that loophole would be great for people who don't care about checking a bag or have a lot of people in their party," Lopinto said. "If you're a family of four and American is going to gate-check your bags, that can save you $100 (versus checking the bags) and you can board earlier."

Jami Counter of travel website TripAdvisor said American's free gate-checking offer was so attractive that it could reduce the amount American makes from checked-baggage fees.

"Why would you ever pay a baggage fee if you can gate-check your bag for free?" he said. "That's a loophole you could drive a truck through. I see that being tightened."

Counter said passengers might swamp gate agents with requests to check their bag for free. "Now their two-minute savings just turned into a 15-minute delay," he said.

American's Doeksen said the airline considered both, but believes any increase in gate-checking and loss of checked-bag fees will be minimal. He noted that passengers can already roll their bags to the gate and check them there for free.

Other carriers are certain to watch American's boarding process closely. Airlines are famous for copying each other's ideas when they work. The frequent-flier program became a staple after American introduced AAdvantage, and other big carriers also imitated American when it introduced fees for checked baggage in 2008 - money from fees helped the airlines return to profitability after the recession.

Southwest and US Airways said Thursday that they have no plans to change their boarding process. United and Delta did not immediately respond when asked if they would make similar changes.