Diio and US DOT O&D (DB1B) Differences

The U.S. DOT O&D survey requires that U.S. airlines submit all of their tickets whose last digit is a 0. Easy, right?

The  DOT fare methodology is a whole different  animal. No one really understands the methodology that the DOT uses to come up with their fares.

We do know this:

1. They somehow mix one-way, round-trip, and multi-leg journeys in their average fare calculations.
2. They use Gross Fares, not Net Fares
3. They intentionally omit routes with passengers under a certain level, saying that the sample size is too small.

More information on Gross Fares:
https://helpdesk.cirium.com/hc/en-us/articles/360059239492-What-are-Gross-Fares-

We use the same exact base data in Diio Mi, but when you look up fares in Diio Mi:

1. We divide the tickets into the various one-way segments that comprise the trip, and we give fares as one-way figures. This makes the comparisons apples to apples. The DOT is comparing apples, oranges, and tomatoes.
2. Gross Fares are what the passengers pay for their tickets, including taxes and fees. You can look up these numbers in Diio Mi, but we prefer to use Net Fares, where we back out the taxes and fees. Net fares are what the airlines get, and that's the number that's important for route development purposes.
3. In one case where we looked at how many routes didn't fit the DOT criteria to be included, it was 20% of that airport's passengers. Seems like an awfully large chunk of traffic to ignore.