Folklore about airline luggage goes like this: To avoid lost bags, carry them on board. Lost luggage is a deep-seated fear in the minds of many travelers, especially those who have heard horror stories — or have their own experiences. But that fear is based on outdated assumptions. Data show a dramatic decline in mishandled bags. Since 2007, mishandled luggage rates have dropped 70 percent globally, according to a report last year from SITA, a company that provides IT services to nearly 90 percent of the world's airlines. In the U.S., the rate is even lower, dropping from more than seven mishandled bag complaints per 1,000 passengers in 2007 to about 2.4 complaints per 1,000 passengers in 2017.

While seeing the three-letter airport destination on a bag tag may reassure passengers their luggage is heading to the right place, it's not the most important information on the sticker. The bar code really gives the assurances of a safe arrival; it is the linchpin in the greatly improved process of checking in, sorting and tracking luggage. Airlines globally have adopted protocol requiring every bag to pass through more scanners, increasing transparency and offering a road map of its whereabouts.

Some airlines, such as Delta, have taken technology a step further. In 2016, Delta rolled out radio-frequency identification (RFID) across its domestic network that allows the airline to send passengers real-time status updates on their bags' location. The Atlanta-based carrier has said it plans to implement the technology at all 340-plus of the airports it serves worldwide.

The odds of a lost bag have gotten significantly smaller, but there's still room for improvement, said Bob Mann, an airline consultant. "If airlines could figure out a way for their customers' bags to be waiting for them at the baggage carousel when they arrived, without question, everyone would check their bag."