Airlines Are Not The Best At Estimating Flight Times The 6 million domestic flights taken last year generated 115 million minutes of delays. NPR's Rachel Martin asks data expert Mona Chalabi of FiveThirtyEight.com what's behind all those delays.
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Airlines Are Not The Best At Estimating Flight Times

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Airlines Are Not The Best At Estimating Flight Times

Airlines Are Not The Best At Estimating Flight Times

Airlines Are Not The Best At Estimating Flight Times

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  • <iframe src="https://www.npr.org/player/embed/393133232/393133233" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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The 6 million domestic flights taken last year generated 115 million minutes of delays. NPR's Rachel Martin asks data expert Mona Chalabi of FiveThirtyEight.com what's behind all those delays.

UNIDENTIFIED WOMAN #1: Fifty-two.

UNIDENTIFIED WOMAN #2: 11:53.

UNIDENTIFIED MAN #1: Twenty-five.

UNIDENTIFIED WOMAN #3: 6.115

RACHEL MARTIN, HOST:

And it's time for some number crunching from our data expert Mona Chalabi from fivethirtyeight.com. And she has given us this number of the week.

UNIDENTIFIED WOMAN #1: One hundred and fifteen million minutes.

MARTIN: That is the total number of minutes domestic flights were delayed last year in the United States. Hey, Mona.

MONA CHALABI: Hi, Rachel.

MARTIN: So that's a lot of pacing around the terminal. How did you discover that number?

CHALABI: Well, actually, I didn't in this case so it was actually my boss, Nate Silver.

MARTIN: Oh, good for you for giving him credit, though.

CHALABI: (Laughter) Yeah. I don't think I can get away with it. He used data from the Bureau of Transportation Statistics that looked at 6 million domestic flights that were taken last year. And he looked at those stats to see which airlines and which roots had the most delays and which ones were the fastest. And that's where we get this number from. Overall, there were 115 million minutes of delays.

MARTIN: All right, so that 115 million minutes of delays. That is a lot of minutes. Why?

CHALABI: Twelve thousand years, Rachel.

MARTIN: Whoa. That really puts it into perspective. So why? What's causing the delays?

CHALABI: Well, the very first thing to say about these government statistics is that they only record a flight as late if it's more than 15 minutes after it's scheduled arrival time. But airlines define their own schedules. There's no single, standard definition of what it means to be on time. And it is sort of a confusing so I will give you an example to describe it. Let's say that you want to fly from San Francisco to LA. That flight should take about an hour and 19 minutes under normal conditions. Virgin America says in its schedule that it will take you there in an hour and 21 minutes. So it's already a couple of minutes longer than you'd expect. And then let's say you actually step on that plane and that flight ends up taking an hour and 30 minutes. Technically, it's got a nine-minute delay. But like I said, that's just based on a schedule that Virgin made up. And the truth is, I don't know how airlines estimate their schedules. There's obviously a little bit of an incentive. Because of this 15-minute cutoff, airlines could possibly overestimate the flight schedule and reduce the chances of them being late.

MARTIN: So they create their own buffer zones and their own sense of timing. So they're setting their own rules, which is confusing.

CHALABI: Kind of, yeah.

MARTIN: I understand there are some cases, too, where some airlines actually underestimate the amount of time it'll take them to make a particular trip. Why would they do that? It seems like they're making it harder on themselves.

CHALABI: Again, it's just really, really hard to say why. What we do know, though, is that some of those airlines do actually manage to beat their promises as you said. So overall last year, passengers saved 35 million minutes because of early rivals in addition to those 115 million minutes of delays.

MARTIN: It's funny, though, even though we may have saved 35 million minutes, we never concentrate on those, right? Like, we always complain about the minutes that we've lost.

CHALABI: (Laughter) Definitely not. Exactly.

MARTIN: So what about airports because, you know, sometimes you're in an airport that is notorious for just having a lot of delays. This happened to me all the time when I lied in San Francisco. That airport seemed to just be cursed. Is that in my mind, or are certain airports, you know, better than others at getting planes where they need to go?

CHALABI: It's not in your mind. Some airports...

MARTIN: (Laughter) Good.

CHALABI: ...Are definitely busier than others. And if an airline is flying in and out of airports that are really inefficient, it just doesn't seem fair to penalize them for being late. So really what we wanted to do first was to figure out which airports are really bad. And to do that, we looked at the average arrival and departure delays for the 30 largest airports in the U.S. And we found that Newark airport in New Jersey came up the worst with an average delay of 25 minutes for departing flights as well as delays of 25 minutes for arrivals coming in. In fact, actually all three major airports in the New York City area - probably no surprise - topped the list of culprits who contributed to delays as well as Chicago O'Hare. But it's also worth calling out the three airports that are so efficient, they actually manage to shave off a few minutes from the flight's target time. Those were San Diego, Portland and Honolulu.

MARTIN: So we should find reasons to fly in and out of those cities.

CHALABI: (Laughter) Exactly.

MARTIN: Try to direct our itineraries through them. So besides rerouting our itineraries, what is the upshot of all of this, Mona? I mean, at the end the day, is there one airline that's really good that I should try to take when I can?

CHALABI: Well, if what you really care about here is speed, then I'd say go with Virgin America. Over the course of 2014, Virgin managed to shave off seven minutes from the average flight that flew within the U.S. United performed the worst adding on average six minutes to a domestic flight. And of course, that's an average of all flights for those airlines. And they do better on some routes than others. But what we can say is that Virgin is often early and that United is often late. And when it comes down to the wire, which I know is going to be your next question, is kind of hard to say.

MARTIN: Why, Mona, why?

(LAUGHTER)

MARTIN: Always with the why.

CHALABI: And it's always with the - it's hard to say. I'm really sorry to disappoint. But one possible explanation is that Virgin might just be doing well because they're not trying to be all things to all people. They fly a relatively small number of routes, mostly to and from major cities on the coasts. And they basically just do it better than other airlines.

MARTIN: Mona Chalabi of fivethirtyeight.com. Thanks so much, Mona.

CHALABI: Thanks, Rachel.

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