Holiday Travel Thanksgiving Airport O'Hare

Peak travel season is officially here in the US, with the Thanksgiving holiday travel period ramping up to its peak. More than 31.6 million Americans are expected to fly during the 12-day period between November 22 and December 3.

With the busy travel period comes the possibility of overbooked flights, as airlines work to maximize capacity.

In many cases when a flight is overbooked, the airline will offer an increasing amount of compensation, and a seat on the next available flight, to find volunteers to give up their seats.

In some cases, though, an airline can’t find the volunteers, which leads to a scenario called involuntary denied boarding (IDB). That’s when a passenger is bumped involuntarily, and although they’re legally entitled to certain compensation and accommodations, it can be an incredibly frustrating experience.

These so-called “IDBs” are rare — airlines try hard to avoid the situation, partly by offering strong incentives to volunteers on overbooked flights, but they do still happen.

The travel website Upgraded Points recently conducted a study to determine which airlines are most likely to bump passengers involuntarily. Although the results show how rare IDBs are, they also show that some airlines have a much better track record than others. (Disclosure: This reporter previously wrote and edited several freelance articles for Upgraded Points.)

Scroll down for the full results. Data are shown as the number of involuntary denied boardings per 100,000 passengers carried.

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14. Delta Air Lines: 0.02 IDBs per 100,000 passengers

In 2018, Delta had the fewest involuntary bumps of the airlines examined, with just 22 out of almost 139 million passengers.

13. Endeavor Air: 0.05 IDBs per 100,000 passengers

Endeavor Air is a wholly owned subsidiary of Delta, which operates regional flights under the Delta Connection brand. Since its flights are marketed, sold, and ticketed by Delta, it makes sense that it has virtually the same IDB rate as its owner.

11. United Airlines: 0.09 IDBs per 100,000 passengers (tied with JetBlue)

Despite a highly publicized incident in 2017, United has a low IDB rate, with only 93 bumps out of almost 100 million passengers. United tied with JetBlue for 11th place.

11. JetBlue: 0.09 IDBs per 100,000 passengers (tied with United)

JetBlue was statistically identical to United in 2018, with 36 involuntary denied boardings out of nearly 38 million passengers.

10. Republic Airways: 1.08 IDBs per 100,000 passengers

Republic Airways is a regional carrier that operates flights on behalf of Delta, United, and American Airlines. Since its flights are sold and ticketed by the airlines it operates for, its bump rate is a function of the rates for those airlines.

9. Allegiant Air: 1.46 IDBs per 100,000 passengers

Las Vegas-based budget airline Allegiant Air bumped 202 passengers out of just under 14 million carried.

8. Southwest Airlines: 1.5 IDBs per 100,000 passengers

Southwest had a whopping 2,423 involuntary denied boardings in 2018, but that was out of almost 162 million passengers.

7. Skywest Airlines: 1.52 IDBs per 100,000 passengers

Skywest is a regional airline operating for the three major carriers — American, Delta, and United — as well as Alaska Airlines, so its IDB rate is a function of the carriers it operates for.

6. Mesa Airlines: 1.56 IDBs per 100,000 passengers

Mesa Airlines operates regional flights primarily for American Airlines and United.

5. American Airlines: 1.95 IDBs per 100,000 passengers

American Airlines had the highest bump rate of the three mainline US carriers, with 2,614 bumps our of nearly 134 million passengers — still a fairly low amount.

4. PSA Airlines: 2.29 IDBs per 100,000 passengers

PSA Airlines is a wholly owned subsidiary of American Airlines, and operates American Eagle regional flights. It had 309 bumps out of 13.5 million passengers.

3. Alaska Airlines: 2.3 IDBs per 100,000 passengers

Alaska Airlines bumped 743 passengers in 2018 out of 32.3 million.

2. Spirit Airlines: 5.57 IDBs per 100,000 passengers

Spirit had 1,529 bumps out of nearly 27.5 million passengers in 2018.

1. Frontier Airlines: 6.28 IDBs per 100,000 passengers

With the highest bump rate of the airlines examined, Frontier had 1,219 involuntary denied boardings out of 19.4 million passengers.