# Are the number of unique passengers per airport counted?

In airport passenger number statistics, all enplanes and deplanes are added to all direct transfers during a year.

So if I travelled 21 times via Heathrow I was counted as 42 passenger movements at LHR.

Is there anywhere statistics that show the number of unique human beings that travelled via an airport?

• This is probably more a question for Travel.SE, although let's see if somebody here has an answer to it. But short of an agency like the TSA, it may be doubtful that anybody can resolve the 8 counts you had with Airline 1 with the 4 counts you had with Airline 2, etc. Unless both airlines share your name with a 3rd party, you're probably getting counted by each airline as a unique customer. And even those counts may be something that airlines regard as sensitive information.
– Ralph J
May 10, 2019 at 5:39
• @RalphJ You could do this via statistical sampling. You stop a random sample of passengers throughout the year, record their names and how they're travelling, and extrapolate that to the overall count. Similar methods are used in trains and transit systems where there are no ticket gates. May 10, 2019 at 16:05

Short answer is no, mostly they are not counted. Even if they have this data it is very unlikely that they publish it.

Assuming that you are not a transfer/transit passenger; meaning you have arrived to airport by ground transportation for your departure and you have left the airport via ground transportation when you have arrived; you will be counted as 42 times in the statistics (21 departure + 21 arrival). This is standard counting method.

If you arrive to the airport by a plane, you stay inside the plane and you leave the airport with the same plane; then you are a transit passenger which is counted 1 time. (You are not a departure or arrival passenger, you are a transit passenger)

If you arrive to the airport by a plane, you leave the plane and you leave the airport with the another plane; then you are a transfer passenger which is counted 1 time. (You are not a departure or arrival passenger, you are a transfer passenger in this case)

So passengers of an airport are basically; departure + arrival + transit + transfer (Note: Exact definitions of transit and transfer might change from airport to airport)

Most of the time, especially in smaller airports, airport management does not record passengers on a unique person basis. They simply don't have the unique identifier for each passenger, such as a passport ID number. So they cannot know if a person is travelling first time or fifth time.

However, there are exceptions of course:

• There are (very expensive) software that allows airport management to record, filter, manage each passenger data with extreme detail. Its work logic is that it records a special text message that airplane sends to airport before arrival.

• For "international" departing/arriving/transfer passengers, this unique traveler information can be obtained from the system of the passport police since they record ID numbers of passports.

• Airlines might have this data separately; however this is not a feasible approach since airlines mostly do not share this info.

It will probably depend on the airport, but for example Amsterdam Schiphol airport publishes these numbers every month (in Dutch).

For example for March, there were in to 5 637 767 passengers, of which 7 453 transito passengers (meaning they left on the same aircraft as they came with).

Of the 5 630 314 non-transito passengers, 3 571 116 where O&D passenger (origin / destination passengers), and 2 059 198 transfer passengers (these are double counted).

So for Amsterdam, we can count 3 571 116 passengers who had their origin or destination in Amsterdam, and 2 059 192 / 2 = 1 029 596 unique transit passenger, making the total 3 571 116 + 1 029 596 = 4 600 712 unique passenges (excluding transito passengers).

Passengers transiting between two flights on separate tickets will still be counted twice (there is no easy way to identify them).

Passengers that travel trough the airport multiple times per month are counted multiple times as well.

• If the OP travelled to AMS four times in a month (and then back home again) using KLM twice and BA twice, would he show up in those numbers as 8 counts, 4 counts, 2 counts, or 1? A methodology that produces the latter result seems to be what he's interested in.
– Ralph J
May 10, 2019 at 15:38