Glossary

A unique identifier assigned by the U.S. Department of Transportation to every motor carrier, broker, and freight forwarder in interstate commerce. The DOT number is the primary key for looking up safety records, insurance, and authority in FMCSA databases. CarrierOk indexes over 4.2 million DOT numbers.

A docket number assigned by FMCSA to for-hire carriers and brokers when they register for operating authority. Unlike DOT numbers (required for all interstate CMV operators), MC numbers are specific to for-hire and brokerage operations. CarrierOk supports lookup by MC number, DOT number, or legal name.

FMCSA-granted permission for a motor carrier, broker, or freight forwarder to operate in interstate commerce. Authority types include common (general for-hire), contract (specific shippers), and broker. CarrierOk tracks authority status changes same-day and alerts subscribers when a carrier's authority lapses or is revoked.

A biennial update form that motor carriers must file with FMCSA reporting fleet size, driver count, mileage, cargo types, and contact info. An MCS-150 older than 2 years is a compliance red flag. CarrierOk tracks MCS-150 filing dates and flags stale filings as a risk signal.

A form filed with FMCSA designating process agents in every state where a motor carrier operates. Process agents accept legal documents on behalf of the carrier. A valid BOC-3 is required before FMCSA activates operating authority. CarrierOk includes BOC-3 agent details in carrier profiles.

FMCSA's composite 1-100 algorithm for prioritizing carriers at roadside inspections. Higher scores mean higher inspection probability. The insurance industry widely uses ISS as a single-number risk indicator because it synthesizes multiple BASIC dimensions. CarrierOk serves ISS scores via the iss_score API field.

A 0-100 peer-relative safety score across seven FMCSA categories: Unsafe Driving, HOS, Vehicle Maintenance, Controlled Substances, Driver Fitness, Hazmat, and Crash Indicator. Higher is worse. CarrierOk computes all 7 BASICs including the two FMCSA withholds from public view.

FMCSA's enforcement and compliance program that uses the Safety Measurement System to identify and prioritize high-risk motor carriers for intervention. CSA drives BASIC percentile scores, warning letters, and compliance reviews. CarrierOk provides all 7 BASIC percentiles, alert flags, and historical trend data via API.

FMCSA's quantitative system for measuring motor carrier safety performance using inspection, crash, and investigation data. SMS produces the BASIC percentile scores that underpin the CSA enforcement program. CarrierOk computes all 7 BASIC percentiles from SMS source data and updates more frequently than FMCSA's monthly cycle.

The percentage of a carrier's roadside inspections that result in an out-of-service order, meaning the driver or vehicle is prohibited from operating until the violation is corrected. National average vehicle OOS rate is approximately 21%. CarrierOk provides both driver and vehicle OOS rates and flags carriers exceeding national averages.

A rating assigned by FMCSA after a compliance review: Satisfactory, Conditional, or Unsatisfactory. An Unsatisfactory rating can trigger an out-of-service order. However, most carriers have never been reviewed and carry no rating — absence of a rating does not indicate safety. CarrierOk includes safety rating status in carrier profiles.

The industry-standard measure of fleet size, counting only vehicles with an engine — trucks and tractors, not trailers. When someone says a carrier has 50 trucks, they mean 50 power units. CarrierOk reports power units separately from trailers via the total_power_units field, sourced from MCS-150 filings.

A license required to operate commercial motor vehicles in the United States, classified as Class A (combination vehicles over 26,001 lbs), Class B (single vehicles over 26,001 lbs), or Class C (hazmat/passenger). CarrierOk reports total CDL drivers per carrier as a fleet composition signal.

Federal regulations limiting commercial driver operating hours to prevent fatigue-related crashes. Key limits include 11 hours driving, 14 hours on-duty, and mandatory 30-minute breaks. HOS violations are one of the 7 BASIC categories tracked in CarrierOk's BASIC percentile data.

A device installed in commercial motor vehicles that automatically records driving time and hours of service. ELDs replaced paper logbooks and are mandated by FMCSA for most interstate carriers since December 2019. HOS violations captured by ELDs feed directly into a carrier's BASIC percentile scores tracked by CarrierOk.

The primary liability insurance every interstate motor carrier must file with FMCSA. Minimum coverage ranges from $750,000 for general freight to $5,000,000 for certain hazmat. CarrierOk shows current BIPD coverage amounts, insurer names, policy numbers, and effective dates via API.

Insurance that protects the value of goods in transit against damage, theft, or loss. Unlike BIPD (which covers third-party liability), cargo insurance covers the freight itself. FMCSA requires minimum cargo coverage for certain authority types. CarrierOk reports cargo insurance amounts and insurer details via API.

A jury award in a trucking accident lawsuit that dramatically exceeds compensatory damages, often surpassing $10 million. Nuclear verdicts have reshaped trucking insurance economics, with average verdicts above $20 million. Courts increasingly hold brokers and shippers liable for negligent carrier selection — making data-driven vetting with tools like CarrierOk essential.

A motor carrier shut down for safety violations that re-registers under a new DOT number to evade its enforcement history. Chameleon carriers carry forward identical operational risk with a clean record. CarrierOk detects chameleon patterns by analyzing shared addresses, phones, principals, and EINs across 4M+ entities.

The illegal practice of a broker or carrier re-brokering a load to another carrier without the shipper's knowledge or consent. Double brokering creates insurance gaps, liability exposure, and fraud risk. CarrierOk's risk signals and authority-type checks help identify carriers associated with double-brokering patterns.

A motor carrier registered with FMCSA for less than 18 months, subject to a New Entrant Safety Audit. New entrants have limited inspection history, making traditional risk scoring unreliable. CarrierOk flags new entrants in risk_signals and provides a New Registrants feed for discovering newly authorized carriers.

The federal agency within the U.S. Department of Transportation that regulates the trucking and bus industries. FMCSA issues operating authority, sets safety standards, and maintains the databases — SAFER, SMS, MCMIS, L&I — that CarrierOk indexes four times daily to power its carrier intelligence platform.

FMCSA's public-facing website for looking up motor carrier safety information, including operating status, authority, and limited inspection data. SAFER does not compute BASIC percentiles, does not serve ISS scores, and updates less frequently. CarrierOk replaces manual SAFER lookups with a comprehensive, API-accessible carrier intelligence platform.