Air travel is shrinking the globe – literally!

UPDATE: See below

The metaphor of air travel shrinking the globe has been around for a long time and it is, to me, one of the most appealing things about travel. I love that I can schlep to the airport, close myself up in a metal tube and not too many hours later emerge in a completely different environment. It is somewhat magical.

imageUnited Airlines seems to be taking the concept of shrinking the globe a step or two farther, however. The new MileagePlus program appears to have actually shrunk the earth, reducing the number of miles between airports throughout their system. In many cases the changes are just a mile or three, maybe up to 10. The overall impact, while de minimis on any individual route, is very real throughout the overall network.

Perhaps most interesting is the official statement from the company on the issue.

As part of combining our two loyalty programs, we did a side-by-side comparison of the mileage calculations used by Continental and United. Of course, we found differences. Most commonly, these differences in calculations were found in locations where airports have physically moved (e.g. DEN, HKG, SIN, etc.). Other differences were found in markets where, when Continental or United added service, the mileage amount chosen was simply set to match other carriers already servicing the market as opposed to doing a new calculation.

In an effort to begin using a single source for all mileage calculations, we refreshed all of our calculation data. The source against which this new mileage is calculates is a standard Great Circle Map (GCM) table. As many of you know, there are several sources for GCM data, and, while they don’t match perfectly, they are also rarely ever off by more than a mile.

I can appreciate the need to reconcile the data every now and then. That part actually makes sense. But if airports have moved then they necessarily moved only in one direction. It would be impossible, for example, for O’Hare to become closer to both LaGuardia and Portland, Oregon at the same time. Strangely, however, that is precisely what the new numbers from United show.

The good news is that the issue is now being addressed in more detail. After being confronted with the fact that the world isn’t really shrinking the company issued another update:

…I apologize for sharing details hastily in my initial post regarding how our mileage distances are being calculated. Turns out it’s a bit more complicated. Mileage amounts are used for a variety of purposes within the company, and we are assessing all the considerations involved. There are more details to come on this topic, and we will have an update for you next week.

So maybe the world really isn’t shrinking and we’re just waiting to find that out officially.

UPDATE (12 March 12): Turns out that the company has basically backed down completely on this move. They’re putting everything back the way it was. Flights previously credited will be updated and new ones will credit correctly going forward.

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Seth Miller

I'm Seth, also known as the Wandering Aramean. I was bit by the travel bug 30 years ago and there's no sign of a cure. I fly ~200,000 miles annually; these are my stories. You can connect with me on Twitter, Facebook, and LinkedIn.


  1. if ORD moved slightly N/S then yes, it IS possible that it got closer to LGA and PDX simulataneously!

  2. I had my next itinerary printed before the changeover and reprinted it after the changeover and I am losing something like 23 miles over the 9 flights (about 9,500 miles). LAX-IAD took the biggest hit, down 8 miles, SFO-LAX is up 1 mile though. Prior to that they still had DEN-ORD as Stapleton, so it was 903 instead of 888.

  3. Did someone write a business case where UA would save $3 million annually by reducing the miles between all airports a de minimus amount? Maybe the function they use is to find the lowest acceptable mileage between city pairs of any data source on the internet

  4. I had noticed this too….I fly EWR SEA pretty much weekly….and suddenly it was 9 miles less.

    Funny that Alaska uses the larger 2042 rather then the now United 2391, so the statement about aligning it with other airlines is not always true.

  5. For the past 10 years CO has credited 2401 miles for SEA-EWR
    AS credits 2401 miles for SEA-EWR
    Neither the SEA nor the EWR airports have moved in the past 40 years lists the distance as 2402 miles

    Now lists the distance as 2392 miles. That seems beyond the margin for error or the possible difference between different locations on the airfield.

    None of the reasons give are believable

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