Glossary
FMCSA glossary
Plain-language definitions for the FMCSA terms you encounter when vetting motor carriers — DOT and MC numbers, CSA scores, BASIC categories, OOS rates, MCS-150, BMC-91, and the rest. Use this as a quick reference or as the source of truth when reading an FMCSA SAFER snapshot.
DOT number (USDOT number)
A unique identifier issued by the Federal Motor Carrier Safety Administration to every commercial motor carrier operating in the United States.
The USDOT number is the carrier's permanent federal identifier. It stays with the company across name changes and is required for any carrier hauling cargo across state lines, hauling hazardous materials, or operating a commercial vehicle above the federal weight threshold. The USDOT number is what every safety record, inspection, and crash report is filed against.
MC number (motor carrier number)
The operating authority docket number issued by the FMCSA that authorizes a for-hire carrier to transport regulated commodities or passengers in interstate commerce.
An MC number is separate from the DOT number. A carrier must have active operating authority (MC, MX, or FF) to legally carry freight for hire across state lines. The status of an MC number — Active, Pending, or Inactive — tells you whether the carrier is currently authorized to do business.
MX number
Mexico-domiciled carrier operating authority docket number.
Issued to Mexican motor carriers authorized to operate in the United States. Functionally analogous to an MC number but specific to cross-border Mexican operators.
FF number (freight forwarder)
Freight forwarder operating authority docket number.
Issued to companies that assemble shipments from multiple shippers, take responsibility for transport, but do not operate the equipment themselves.
CSA (Compliance, Safety, Accountability)
The FMCSA's safety enforcement program that scores motor carriers across seven categories of safety performance, using two years of roadside inspection and crash data.
CSA is the umbrella enforcement initiative. Within CSA, the Safety Measurement System (SMS) generates the BASIC scores that flag carriers for intervention. CSA scores are public for most categories and are the primary tool brokers and shippers use to assess on-road risk.
BASIC (Behavior Analysis and Safety Improvement Category)
One of seven safety behavior categories the FMCSA uses to score motor carriers under the CSA program.
The seven BASICs are: Unsafe Driving, Hours-of-Service Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, Hazardous Materials Compliance, and Crash Indicator. Each BASIC has a percentile score and an FMCSA-set threshold. A carrier whose percentile exceeds the threshold is flagged for FMCSA intervention.
SMS (Safety Measurement System)
The FMCSA database that calculates BASIC scores from inspection and crash data and prioritizes carriers for intervention.
SMS pulls inspection results and reportable crash data into a single scoring system, refreshed monthly. SMS scores are not the same as a Safety Rating — they are an operational risk signal, not a federal rating.
Safety rating
A formal FMCSA-issued rating — Satisfactory, Conditional, Unsatisfactory, or Unrated — assigned to a carrier after a Compliance Review.
Unlike CSA scores, the Safety Rating is a regulatory determination. A Conditional rating means the carrier has not maintained adequate safety management controls. Unsatisfactory means the carrier is unfit to operate; an Unsatisfactory rating triggers an order to cease operations. Many active carriers are Unrated, simply because they haven't had a Compliance Review yet.
OOS rate (out-of-service rate)
The percentage of a carrier's roadside inspections that resulted in the vehicle or driver being placed out of service.
Reported in three forms: Vehicle OOS rate, Driver OOS rate, and Hazmat OOS rate. National averages are roughly 20% for vehicle, 5.5% for driver, and 4.2% for hazmat. Carriers significantly above the national average are higher operational risk.
Out-of-service order
A regulatory action prohibiting a carrier, vehicle, or driver from operating until specific safety violations are corrected.
Issued by federal or state inspectors. A vehicle OOS order grounds the truck; a driver OOS order pulls the driver; a carrier-level OOS shuts down operations entirely. Distinct from the OOS rate, which is a percentage; an OOS order is an active enforcement action.
MCS-150
The biennial Motor Carrier Identification Report that every USDOT-registered carrier must file every two years to keep its registration active.
Required even if the carrier's information has not changed. The filing month is based on the last two digits of the USDOT number. Failure to update can result in deactivation and Unsatisfactory operating authority status.
BMC-91 / BMC-91X
The form that documents a motor carrier's bodily injury and property damage (BIPD) liability insurance filing with the FMCSA.
Required minimums are typically $750,000 for general freight, $5M for many hazmat hauls, and up to $5M for passenger carriers. A current BMC-91 or BMC-91X on file is required for active operating authority. Cancellation triggers an authority revocation within 30 days.
BMC-34
Cargo insurance filing form for household goods carriers, documenting coverage for the freight being transported.
Distinct from BMC-91 (which covers liability for injury and property damage). Required for household-goods carriers. General freight haulers are not federally required to carry cargo insurance, though shippers and brokers typically demand it.
BOC-3
The blanket designation of process agents in every state where a carrier may operate, required for active operating authority.
A process agent is a legal representative authorized to accept court papers on the carrier's behalf. The BOC-3 is filed once and remains valid until the carrier cancels it or changes process agents.
Compliance Review (CR)
An on-site audit by FMCSA investigators of a carrier's safety records, driver qualification files, hours-of-service compliance, and maintenance documentation.
Triggered by elevated CSA scores, a fatal crash, a complaint, or random selection. The CR result determines the carrier's federal Safety Rating. Most carriers go their entire operating life without one.
New Entrant Safety Audit
A required safety audit conducted within the first 12 months of a carrier obtaining its USDOT number.
The audit verifies that the new carrier has basic safety management systems in place. Failure of the audit results in revocation of new-entrant status.
ELD (electronic logging device)
A federally mandated device that automatically records a driver's hours of service.
Required for most interstate commercial drivers since December 2017. Replaces paper logs. ELD data is admissible in inspections and must be presentable at roadside.
HOS (hours of service)
Federal regulations limiting how many consecutive hours a commercial driver can drive and work before mandatory rest.
Core property-carrier HOS rules: 11-hour driving limit within a 14-hour on-duty window, 10 consecutive hours off-duty between shifts, 70 hours over 8 days. Violations are tracked under the HOS Compliance BASIC.
DVIR (driver vehicle inspection report)
The pre-trip and post-trip vehicle inspection report drivers are required to complete daily.
Federal regulation 49 CFR 396.11. Defects identified on a DVIR must be repaired before the vehicle is operated.
Drug & Alcohol Clearinghouse
A federal database operated by the FMCSA that tracks drug and alcohol violations by commercial drivers.
Employers must register, query the Clearinghouse before hiring and annually for current drivers, and report violations. Active since January 2020.
Hazmat (hazardous materials) flag
A designation indicating a carrier is authorized to transport hazardous materials.
Hazmat carriers face higher minimum insurance requirements, additional driver qualification rules (HM endorsement on CDL), and a separate Hazmat BASIC score. Brokers verify this status before tendering hazmat freight.
For-hire authority
Authorization to transport freight for compensation, as opposed to private (own-goods) operation.
For-hire carriers must hold operating authority and meet insurance filing requirements. Private carriers transporting only their own goods are exempt from some of these requirements.
Common vs contract authority
Common-carriage authority allows transport for the general public; contract authority limits operation to specific shippers under signed contracts.
Common authority is broader. Many carriers hold both. Brokers verify whichever authority covers the type of work being tendered.
Double brokering
The practice of one broker re-brokering a load to another carrier or broker without the shipper's consent — a leading cause of carrier fraud and unpaid loads.
Often used as a fraud vector: a fraudulent party books a load under a legitimate carrier's identity, then re-brokers it to a real hauler, collects the broker payment, and never pays the hauler. Vetting for double brokering risk involves checking authority age, insurance, and operating history.
SAFER (Safety and Fitness Electronic Records)
The FMCSA's public web portal for looking up motor carrier safety and registration data.
SAFER's Company Snapshot is the canonical free source for authority status, fleet size, and inspection summaries. The interface is dated and slow; many vetting tools (including FlitIQ) repackage the same underlying data with better search, alerts, and pipeline integration.
Crash Indicator
A CSA BASIC that scores the frequency and severity of reportable crashes involving the carrier's vehicles over the past 24 months.
Crash Indicator scores are not made public for most carriers, but the underlying crash data is. The score factors in crash severity (fatal, injury, towaway) and the carrier's exposure (power units, vehicle miles).
Power units
The count of self-propelled vehicles (tractors, straight trucks, buses) operated by a carrier.
Reported on the MCS-150. Used by FMCSA to calculate normalized rates (inspections per unit, crashes per unit) and by brokers to gauge carrier scale.
Drivers (driver total)
The number of commercial drivers employed by the carrier, as reported on the MCS-150.
Used alongside power units to gauge carrier size. The ratio of drivers to power units can also flag staffing concerns — a fleet of 100 trucks with only 50 drivers can't run all its equipment.
Inspection level (Level I–VI)
The six standardized roadside inspection levels defined by the Commercial Vehicle Safety Alliance.
Level I is the most thorough (driver + vehicle, ~37 inspection items). Level II is walk-around without crawling under the truck. Level III is driver-only. Level V is vehicle-only without the driver present. Levels IV and VI are special-purpose.
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