One of those “I knew it!” stories appeared in the New York Times recently. This one was about how average airline delay times were actually much longer than airlines were required to report, as least for passengers. The story noted that with air travel at record highs this year, more than a quarter of all flights within the United States were at least 15 minutes late and were delayed for considerably longer times than in the past.

Fifteen minutes doesn’t sound like much, but don’t be fooled. If, for instance, your flight was an hour late and you missed a connection, causing you to wait another four hours for the next flight, all the airlines count is the one-hour delay. Ditto if the missed connection means you are put up overnight because the rebooked flight to your destination is the next day.

If your flight is canceled, no delay is counted. (What a strange incentive that creates for airlines.)

Or if your flight taxis out of the gate on time, sits on the tarmac for two hours and then taxis back to the terminal, no delay is recorded.

The story cites a researcher from the Massachusetts Institute of Technology who estimated in 2000 that the average delay was about 25 minutes, or 66 percent higher than what the Transportation Department reported. Since then, passengers have been stranded at airports more often and for longer periods. They don’t call them terminals for nothing.

One cause of the discrepancy, as the Times notes, is that airlines are counting how long their planes are delayed, not how long their passengers are. Plane delays may be interesting to the traveling public, but passenger delays are much more useful. And certainly not all the delays are the fault of the airlines – airport congestion or labor problems or weather all can affect on-time departures and arrivals.

But passengers aren’t looking for scapegoats; they want assurance that if they book a business or vacation trip, they have a reasonable chance of making their meeting or tee time. Failing that, a more accurate assessment of the chances that they will be stuck watching airport TV until late into the night would be appreciated.