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Regulatory Guidance

Welcome to the FMCSA Guidance Portal. This web portal is a searchable, indexed database that contains and links to all guidance documents in effect from the Federal Motor Carrier Safety Administration. The guidance documents lack the force and effect of law, unless expressly authorized by statute or incorporated into a contract.

To comment on any guidance document, or to request issuance, reconsideration, modification, or rescission of any guidance document, please identify the guidance document in your request and send it to: FMCSAguidance@dot.gov. NOTE: The FMCSAguidance mailbox is not intended to serve as a mailbox for general inquiries. For inquiries that go beyond the limited purpose of the FMCSAguidance mailbox, please call FMCSA's Information Line (800-832-5660) or visit FMCSA's "Contact Us" page to send your inquiry to the appropriate mailbox.

Subject Agency Identifier Topic Issued Date
What markings must be displayed on a CMV when used by two or more motor carriers? FMCSA-RG-390.21-Q001 Marking of CMVs used by multiple carriers
Section 390.23 provides that parts 390 through 399 do not apply to any motor carrier or driver operating a CMV to provide direct assistance in an emergency. Is a motor carrier or driver required to keep a record of the driver’s on-duty or driving time whi FMCSA-RG-390.23-Q002 Driver recordkeeping while providing assistance in an emergency
What constitutes a “serious pattern” of violations? FMCSA-RG-390-SPECIALTOPICS-Q01 What is a “serious pattern” of violations?
Applicability of FMCSRs when CMVs are off the road FMCSA-RG-390.3T-Q016 Applicability of FMCSRs when CMVs are off the road
Are persons who operate CMVs for the personal conveyance of their friends or family members ‘‘private motor carriers of passengers (nonbusiness)’’ as defined in §390.5? FMCSA-RG-390.3T-Q018 Parameters of “private motor carriers of passengers”- Nonbusiness
If, after December 18, 1995, a Mexico-based driver is found operating beyond the boundaries of the four border States allowed by the North American Free Trade Agreement (NAFTA), is that driver in violation of the FMCSRs? If so, which one? FMCSA-RG-390.3T-Q022 Mexico-NAFTA
What is the applicability of the FMCSRs to motor carriers owning and operating school buses that contract with a municipality to provide pupil transportation services? FMCSA-RG-390.3T-Q014 Applicability of FMCSRs to school bus contractors
Do the definitions of "farm", "farmer" and "agricultural crops" apply to greenhouse operations? FMCSA-RG-390.5T-Q001 Applicability of farm-related definitions to greenhouse operations
Is a vehicle used to transport or tow an anhydrous ammonia nurse tank considered a CMV and subject to FMCSRs? FMCSA-RG-390.5T-Q002 Applicability of FMCSRs to vehicles towing nurse tanks
If a vehicle’s GVWR plate and/or VIN number are missing but its actual gross weight is 10,001 pounds or more, may an enforcement officer use the latter instead of GVWR to determine the applicability of the FMCSRs? FMCSA-RG-390.5T-Q003 Use of actual GVW when GVWR and/or VIN plate missing