DOT Data Reporting Training: OD40 & T100

1. The "40 Percent Rule" (Sampling Strategy)

The DOT transitioned from a 10% quarterly sample to a 40% monthly sample to improve data granularity. For a new hire, the most critical part is knowing which tickets to include in the report.

The Selection Rule: To achieve a valid 40% sample, you must collect every ticket where the last digit of the ticket number (or Record Identification Number) is:

0, 2, 7, or 9

If your system does not use standard ticket numbers, you must use a DOT-approved alternative method to ensure a random 40% distribution.

2. OD40 vs. T-100: What's the Difference?

While both reports are submitted to the Bureau of Transportation Statistics (BTS), they serve different purposes:

Feature	O&D40 Report	T-100 Report
Focus	Passenger Itinerary & Fares (Revenue)	Flight Capacity & Traffic (Operational)
Data Level	Market Level (Where they started/ended)	Segment Level (Each leg of the flight)
Frequency	Monthly (Due 45 days after month-end)	Monthly (Due 30 days after month-end)
Key Elements	Fares, Taxes, Full Itinerary, Dwell Time	Available Seats, Passengers, Cargo, Fuel

3. Data Collection Steps

1

Identify Flown Lift: O&D data is reported when a ticket has been recognized as flown in the revenue accounting system.

2

Apply the 40% Filter: Filter the month's flown tickets for those ending in 0, 2, 7, or 9.

3

Categorize the Ticket:

Category 1: Your airline issued the ticket (Report everything).
Category 2: Another airline issued it, but you are the first lifting carrier on the itinerary (Report it if the issuer isn't an O&D reporter).

4

Format & Validate: Files must be in .CSV format. Ensure the RIN (Record Identification Number) is sequential and includes your Carrier Code + Year + Month (e.g., UA20260100000001).

4. Common Pitfalls

Surface Segments: If a passenger takes a bus or train as part of the ticket, use code BUS or TRN for the operating carrier and -1 for dwell time.
Tax Accuracy: The "Total Amount" must include taxes. If taxes exceed $1,999, it usually triggers a flag and needs explanation.
T-100 Alignment: The DOT uses T-100 data to validate OD40. If T-100 shows 10,000 passengers on a route, but OD40 only shows 1,000 (10% instead of 40%), you will receive a data quality warning.