DOT & FMCSA compliance glossary
The acronyms and terms you'll meet running a motor carrier, explained in plain language — with the regulation behind each one.
- Accident register
A list a motor carrier must keep of every DOT-recordable crash its CMVs were in. A recordable crash is one with a death, an injury treated away from the scene, or a vehicle towed away because of disabling damage. Carriers must keep the register for 3 years after each crash, and auditors ask to see it.
- Automatic-failure violations
A short list of violations that make a new carrier fail its New Entrant Safety Audit no matter how well the rest of the audit goes. Examples include having no drug and alcohol testing program, no random testing, using a driver without a valid CDL or medical card, and having no insurance. Two items, missing logs and missing annual vehicle inspections, count only if 51% or more of the records checked have the problem.
- BASICsBehavior Analysis and Safety Improvement Categories
The seven categories FMCSA uses to score carrier safety in CSA: Unsafe Driving, Crash Indicator, Hours-of-Service Compliance, Vehicle Maintenance, Controlled Substances/Alcohol, Hazardous Materials Compliance, and Driver Fitness. Each one is built from inspection, crash, and investigation data. A high score in any BASIC can lead to a warning letter or an investigation.
- BOC-3Designation of Agent for Service of Process
The form that names a process agent in each state where you operate, so legal papers can be served on your company there. For-hire carriers, brokers, and freight forwarders must have a BOC-3 on file before FMCSA will grant operating authority. Only one current BOC-3 can be on file, and most carriers use a blanket process agent company to file it.
- C/TPAConsortium/Third-Party Administrator
A service company that runs DOT drug and alcohol testing for employers. A C/TPA can manage the random testing pool, schedule tests, keep records, and work with the lab and the MRO. Owner-operators who drive for their own company must join a consortium for random testing, because they cannot run a random pool of one.
- CDLCommercial Driver's License
The state-issued license needed to drive the heaviest trucks and buses. You need a CDL for a vehicle or combination rated at 26,001 pounds or more, a vehicle built to carry 16 or more people including the driver, or any vehicle that must carry hazmat placards. CDLs come in Class A, B, and C, and carriers must check that each driver has the right class and endorsements.
- ClearinghouseFMCSA Drug and Alcohol Clearinghouse
FMCSA's online database of CDL drivers' drug and alcohol violations, such as positive tests and test refusals. Employers must run a full query before a new CDL driver starts and query every CDL driver at least once a year. A driver with an unresolved violation may not drive a CMV until finishing the return-to-duty process.
- CMVCommercial Motor Vehicle
A vehicle used in interstate commerce that is covered by the federal safety rules. It is a CMV if it weighs or is rated at 10,001 pounds or more, is built or used to carry 9 to 15 passengers for pay, is built or used to carry 16 or more passengers without pay, or hauls hazmat that needs placards. If you run even one CMV across state lines, most FMCSA rules apply to you.
- Compliance review
A detailed FMCSA or state investigation of a carrier's safety records, done on-site or remotely. It checks areas like driver files, drug and alcohol testing, hours of service, maintenance, and insurance. A full compliance review can give your company a new safety rating, so it can affect whether you are allowed to keep operating.
- Corrective action plan (CAP)
A written plan that shows FMCSA how your company fixed the problems found in an audit or investigation and how you will stop them from happening again. A new carrier that fails its safety audit must fix the problems within 60 days, or 45 days for passenger and hazmat carriers, or its registration is revoked. A strong CAP with proof attached can also support a request to upgrade a safety rating.
- CSACompliance, Safety, Accountability
FMCSA's program for finding unsafe carriers and stepping in early. It uses roadside inspections, crash reports, and investigation results to measure each carrier's safety in the BASICs. Brokers, shippers, and insurers often look at CSA data, so poor scores can cost you business as well as bring an investigation.
- DataQs
FMCSA's online system for asking that inspection, crash, or other safety data be reviewed and corrected. Carriers and drivers use it to challenge a violation they believe is wrong or a crash that was not preventable. The request goes to the agency that reported the data, and a fix can lower your CSA scores.
- DQ fileDriver Qualification File
The file a carrier must keep for each CMV driver to prove the driver is qualified. It holds items such as the job application, motor vehicle records, the road test or CDL copy, the annual review, the medical certification record, and the safety history check with past employers. You must keep it while the driver works for you and for 3 years after. Missing DQ items are one of the most common audit findings.
- DVIRDriver Vehicle Inspection Report
A written report a driver makes at the end of the day about the condition of the truck and trailer, covering items like brakes, lights, tires, and coupling devices. Drivers of property-carrying vehicles only need to fill one out when they find or are told about a defect. Defects that affect safety must be fixed and signed off before the vehicle runs again, and the carrier keeps each DVIR for 3 months.
- ELDElectronic Logging Device
A device connected to the truck's engine that records a driver's hours of service automatically. Most drivers who must keep logs are required to use an ELD that is on FMCSA's registered list. Some drivers are exempt, such as short-haul drivers using time records, drivers who keep logs no more than 8 days in any 30-day period, and trucks with engines older than model year 2000.
- For-hire vs. private carrier
A for-hire carrier hauls other people's freight or passengers for pay. A private carrier moves its own goods as part of its own business, like a builder hauling its own materials. Both follow the same safety rules and need a USDOT number for interstate CMVs, but for-hire carriers generally also need operating authority (an MC number).
- GCWRGross Combination Weight Rating
The maximum loaded weight of a power unit plus everything it tows, as set by the manufacturer. Rules use GCWR to decide whether a combination is a CMV and which CDL class a driver needs. For example, Class A covers combinations with a GCWR of 26,001 pounds or more when the towed unit is rated over 10,000 pounds.
- GVWRGross Vehicle Weight Rating
The maximum loaded weight of a single vehicle, as set by the manufacturer and shown on the door label. A vehicle with a GVWR of 10,001 pounds or more used in interstate commerce is a CMV. At 26,001 pounds or more, the driver needs a CDL.
- Hours of service (HOS)
Federal limits on how long CMV drivers may drive and work. For property-carrying drivers, the main limits are 11 hours of driving after 10 hours off duty, no driving after the 14th hour on duty, a 30-minute break after 8 hours of driving, and a 60- or 70-hour limit over 7 or 8 days. Passenger carriers have different limits. HOS violations are a common reason for roadside out-of-service orders and audit findings.
- IFTAInternational Fuel Tax Agreement
An agreement among US states and Canadian provinces that lets a carrier report and pay fuel taxes through one base state. Carriers with qualified motor vehicles, generally those over 26,000 pounds or with three or more axles, that travel in more than one member jurisdiction need an IFTA license and decals. You file a fuel tax return every quarter showing miles driven and fuel bought in each jurisdiction.
- Interstate vs. intrastate
Interstate commerce is transportation that crosses state lines, or a trip inside one state that is part of a longer move to or from another state or country. Intrastate commerce stays within one state from start to finish. Interstate carriers follow the federal FMCSA rules, while intrastate carriers follow their state's rules, and many states also require a USDOT number.
- IRPInternational Registration Plan
An agreement that lets heavy vehicles that travel in several states and Canadian provinces register through one base jurisdiction with one apportioned plate and cab card. Registration fees are split among jurisdictions based on the miles you drive in each. It generally applies to power units over 26,000 pounds or with three or more axles used across jurisdictions.
- MC numberMotor Carrier number
The docket number FMCSA assigns when it grants operating authority to a for-hire carrier. Brokers and shippers often ask for it to confirm you are allowed to haul their freight. FMCSA has proposed eliminating MC numbers and using only the USDOT number, but it has not done so, and Phase II of Motus explicitly leaves that change out.
- MCS-150Motor Carrier Identification Report
The form that gives FMCSA your company's basic details, such as address, type of operation, cargo, number of trucks, number of drivers, and miles driven. You file it to get a USDOT number and must update it every 24 months, in a month set by the last two digits of your USDOT number. If you miss the update, you can face penalties and your USDOT number can be deactivated.
- Medical examiner's certificate
Proof that a CMV driver passed a DOT physical given by an examiner listed on FMCSA's National Registry of Certified Medical Examiners. A certificate is valid for up to 24 months, and the examiner can issue a shorter one. Since June 23, 2025, a CDL driver's medical status is sent to the state and shows on the driver's CDLIS record, so carriers check it through the MVR. Using a driver who is not medically qualified is an automatic-failure violation on a new entrant audit.
- Motus
FMCSA's new online registration system, which replaced the Unified Registration System and the FMCSA Portal. It opened to all registrants on May 19, 2026, and is where carriers handle their FMCSA registration. Motus is not an ELD and has nothing to do with logging hours of service.
- MROMedical Review Officer
A licensed doctor who reviews DOT drug test results before they go to the employer. If a test is positive, the MRO talks with the driver to see if there is a valid medical reason, such as a prescription. The MRO then reports the verified result to the employer and reports verified violations to the Clearinghouse.
- MVRMotor Vehicle Record
A driver's driving record from the state that issued the license, showing violations, suspensions, and license status. Carriers must get an MVR from every state where a new driver held a license in the past 3 years within 30 days of hire. After that, they must pull and review an MVR for each driver at least once every 12 months and keep it in the DQ file.
- New entrant program
FMCSA's safety monitoring period for carriers that just got a USDOT number to operate in interstate commerce. It lasts 18 months, and during that time the carrier must pass a New Entrant Safety Audit. Carriers that pass and keep a clean record finish the program, while carriers that fail and do not fix the problems lose their registration.
- New entrant safety audit
A review of a new carrier's safety management that FMCSA or a state partner does during the new entrant program. By law it should happen within 12 months after you start operating, or within 120 days for passenger carriers. The auditor checks driver files, drug and alcohol testing, hours of service, maintenance records, insurance, and the accident register. Any automatic-failure violation means you fail and must submit corrective action.
- Out-of-service order
An FMCSA order that stops a carrier from operating. It can follow a final Unsatisfactory safety rating, a failed new entrant audit that was not fixed, a finding that the carrier is an imminent hazard, or unpaid civil penalties. Operating while under an out-of-service order brings serious penalties and can lead to revocation of your registration.
- Process agent
A person or company in a state who accepts court papers on behalf of a carrier, broker, or freight forwarder. Motor carriers with operating authority must name a process agent in each state where they operate, using the BOC-3 form. Most carriers hire a blanket process agent company that covers all the required states.
- Random testing pool
The list of CDL drivers from which drivers are picked by chance for unannounced drug and alcohol tests. Each driver must have an equal chance of being picked each time, and tests must be spread through the year. For 2026, the minimum yearly rates are 50% for drugs and 10% for alcohol. Having no random testing program is an automatic-failure violation on a new entrant audit.
- RODSRecord of Duty Status
A driver's log of each day's time off duty, in the sleeper berth, driving, and on duty not driving. Today most drivers keep RODS on an ELD, while some exempt drivers still use paper logs. Carriers must keep RODS and supporting documents for 6 months. Failing to require logs for 51% or more of the records checked is an automatic-failure violation on a new entrant audit.
- SAFERSafety and Fitness Electronic Records
FMCSA's public website where anyone can look up a carrier by USDOT number, MC number, or name. Its Company Snapshot shows registration and authority status, fleet size, inspection and crash counts, safety rating, and the date of the last MCS-150 update. Brokers and shippers use it to vet carriers, so make sure your information is correct.
- Safety rating
FMCSA's official grade of whether a carrier has adequate safety management controls: Satisfactory, Conditional, or Unsatisfactory. Ratings come from compliance reviews, and many carriers are simply unrated. A final Unsatisfactory rating bars you from operating CMVs, and a Conditional rating can make brokers, shippers, and insurers hesitate.
- SMSSafety Measurement System
The FMCSA tool that turns inspection, crash, and investigation data into a carrier's scores in each BASIC. It updates monthly, uses the past 24 months of data, and ranks carriers against similar carriers by percentile. Scores above FMCSA's thresholds flag a carrier for possible warning letters or investigations.
- UCRUnified Carrier Registration
A yearly registration and fee for companies that operate in interstate commerce, including for-hire and private motor carriers, brokers, freight forwarders, and leasing companies. For carriers, the fee depends on the number of vehicles in the fleet. You must register for each year, and running without current UCR can lead to roadside fines.
- USDOT number
The unique number FMCSA assigns to identify a company that runs CMVs. You need one if you operate CMVs in interstate commerce or haul hazmat that requires a safety permit, and many states require one for intrastate carriers too. It is shown on your trucks and is how FMCSA tracks your inspections, crashes, audits, and compliance.