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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
Must additional lamps that are not required be operative if all required lamps are operative? FMCSA-VEH-393.24-Q01 Operation of additional lamps
Are lighting devices on mobile homes/house trailers required to be permanently mounted? FMCSA-VEH-393.25-Q01
What constitutes a “serious pattern” of violations? FMCSA-RG-390-SPECIALTOPICS-Q01 What is a “serious pattern” of violations?
Are there any special lighting requirements for large containers? FMCSA-VEH-393.25-Q02 Lighting requirements for large containers
What are the lighting requirements when a container assumes the structural requirements of a trailer? FMCSA-VEH-393.25-Q03 Lighting requirements for containers as structural trailers
Does a frame channel of a CMV constitute a protective ‘‘sheath or tube’’ as specified in §393.28? FMCSA-VEH-393.28-Q01 Frame channel as protective “sheath or tube”
Must all trailers be equipped with overload protective devices? FMCSA-VEH-393.28-Q02 Overload protective devices for trailers
May a system such as ‘‘driveline brakes’’ be used as an emergency brake provided it complies with the requirements of § 393.52? FMCSA-VEH-393.40-Q01 “Driveline brake” as emergency brakes
May the ‘‘park’’ position of a CMV’s transmission be used as a parking brake to comply with the § 393.41? FMCSA-VEH-393.41-Q01 “Park” position as parking brake
May a driver record sleeper berth time as off-duty time on line one of the record of duty status? FMCSA-HOS-395.1-Q26 Hours of Service Exceptions