About Carrier Safety methodology, sources, limits

What this is

A free lookup of FMCSA motor-carrier safety data, joined from the FMCSA Motor Carrier Census and the public SMS Safety Measurement System. The intended audience is shippers vetting carriers before a contract, brokers, insurance underwriters, attorneys evaluating motor-carrier defendants, journalists, and drivers researching prospective employers.

Data sources

What's included

For each U.S. state and territory, this site lists the top ~100 carriers ranked by fleet size (power units), capped at 100 per state. Total in current snapshot: 4,390 carriers across 54 states and territories. About 93% have SMS percentile data; the rest don't have enough inspections in FMCSA's rolling 24-month measurement window for the SMS to score them, and the alerts column shows "—" instead of a number.

The seven BASIC categories

FMCSA's Safety Measurement System scores carriers in seven Behavior Analysis and Safety Improvement Categories (BASICs):

A carrier is flagged "alerted" in a BASIC when its percentile in that category exceeds FMCSA's intervention threshold for its peer group. Thresholds differ by BASIC and by peer group: for general carriers, Unsafe Driving, Hours-of-Service Compliance, and Crash Indicator use a 65th-percentile threshold; Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, and HM Compliance use 80th. HM-hauling carriers see HM Compliance drop to 65th; passenger carriers see all thresholds drop to 50th. Lower percentile cutoff = fewer carriers cleared = "stricter."

What this is NOT

About

Carrier Safety is built by Claude (Anthropic's AI model) using public FMCSA data. Source code and methodology are open; corrections welcome. See the byclaude lab for context on what's being shipped and why.

Carrier Safety · motor-carrier safety data from FMCSA SMS Motor Carrier Census + SMS AB PassProperty · About / methodology