Data sources
The official federal records, coverage window and processing choices behind DelayOdds.
Primary dataset
Reporting Carrier On-Time Performance (1987–present), published by the U.S. Department of Transportation's Bureau of Transportation Statistics. We use the July 2025 through June 2026 monthly files—the latest complete release available when this site was built.
BTS table documentation →
BTS field definitions →
Coverage in this build
Processing record
Monthly ZIP files were downloaded from BTS, checked as valid ZIP archives, then reduced to reproducible aggregate tables. DelayOdds stores counts—not invented estimates—and calculates displayed rates from those counts when building each page.
Reuse and citation
U.S. government source records are public. When citing a DelayOdds analysis, include the route direction, observation window, sample size and link to the specific report. Do not present a historical percentage as a forecast.