Two FMCSA files, one carrier, different answers: what a parity check found in public U.S. trucking data
If you build software for trucking, sooner or later you join your data to FMCSA's. The agency publishes carrier registration data openly on data.transportation.gov, keyed by USDOT number, and many brokers, insurers and TMS products rely on it. I wanted to know two things. First, does the same FMCSA dataset return the same records through its paginated API as through its CSV export? Second, when…
Two U.S. trucking data publications from the Federal Motor Carrier Safety Administration (FMCSA) revealed discrepancies in their records after a parity check. The Company Census File, refreshed daily, was compared to the Motor Carrier Census, published monthly. For Iowa, both datasets yielded identical record counts of 58,074 and 8,378, respectively, with no differences in 25 fields.
However, 229 carriers appeared exclusively in the SMS Input file, while 1,184 were only in the Company Census. Additionally, 3,757 field discrepancies were observed between the two publications for matched carriers, mainly due to timing differences such as the SMS file reflecting registrations up to September 24, 2026, while the Company Census was based on November 7, 2026.
Most of these discrepancies were explained by carriers filing a newer MCS-150 form between the two snapshots. However, about 1,025 active Census carriers in Iowa were missing from the SMS file without a recent filing, and 938 of the 1,137 power unit differences had the same filing date in both datasets. The hazmat flag difference between the two datasets stemmed from different definitions, with the SMS file indicating carriers subject to the placardable hazardous materials threshold, while the Company Census simply marked carriers as hazmat.
Overall, the data revealed that the two publications answer different questions and the discrepancies were due to differences in their definitions rather than inaccuracies in the data itself.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
