Why one particular bag is now an even better deal for travelers

If you’re a cheapskate flyer, here’s some welcome news: American Airlines will allow travelers in its cheapest Basic Economy class to bring aboard a carry-on bag for free, starting Sept. 5.

This brings it into alignment with Delta’s cheapest class, and although United still bans carry-ons in its cheapest seats, I wouldn’t be surprised if that doesn’t change soon, too, if only due to competitive pressure.

More than ever, carry-ons are a good deal for travelers. The top four reasons:

1. Carry-ons are free or cheap

Most airlines do not charge for carry-ons, regardless of what class you’re in. Exceptions to this include the ultra-discount carriers: Allegiant, Frontier and Spirit. These airlines do allow very small bags for free providing they fit under a seat -- and that might do it for a weekend trip. But free bags aren’t the only reason to use a carry-on.

2. Carry-ons won’t get lost

It doesn’t happen often these days, but airlines still lose bags and there’s nothing like watching an empty luggage carousel go round-and-round as it slowly dawns on you that your bag is pulling a no-show. This cannot happen with a carry-on because it’s a bag that travels by your side, and rides over your head in the bin or squashed between your feet. Tip: Carry-ons that are too big may be taken from you at the boarding gate so be sure to adhere to your airline’s size and weight limits. When shopping for a bag, the airlines say, include the wheels in any measurements you take.

3. Carry-ons won’t get left behind

Sometimes, when airlines run into weather or mechanical delays, you might hear something like this: “Run fast and you might make the last flight out over at Gate 29!” You, of course, are at Gate 2 so it’s a real sprint. Will your carry-on make it? Of course. Will the airline be able to switch a checked bag from the cargo hold of one plane to another? Maybe, but don’t hold your breath.

4. Carry-ons won’t add delays to vacations or homecomings

Once the plane lands, most folks head for the baggage carousel, where they stand around for another half hour or so wondering why everyone in the world has a black bag. If you’d like to avoid this boring, crowded scene, use a carry-on. You skip the carousel and begin your adventure immediately. You’ll also beat the crowds waiting for taxis, Ubers and Lyfts.

A final note: The TSA says new 3D scanners are coming to the nation’s airports, and one is already at John F. Kennedy Airport in New York City. It is supposed to help screeners get a better view of even cluttered bags, and a TSA administrator has been quoted as saying ultimately passengers may not have to take anything out of carry-ons, though that is probably five years away. Still, it's something to look forward to.