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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
How does compensation relate to on-duty time? FMCSA-HOS-395.2-Q10 Hours of Service Definitions
Does § 393.41 prohibit air brake systems from being equipped with a means to release the spring brakes for purposes of towing disabled vehicles in emergency situations? FMCSA-VEH-393.41-Q02 Releasing spring brakes for towing
What difference, if any, is there between a warning device and a warning signal? FMCSA-VEH-393.51-Q05 What’s the difference between a warning device and a warning signal?
Is a heat shield mandatory on a vertical exhaust stack? FMCSA-VEH-393.83-Q01 Heat shield on vertical exhaust stack?
May a driver domiciled in the United States comply with the Canadian hours of service regulations while driving in Canada? FMCSA-HOS-395.3-Q05 Hours of Service Maximum Driving Time
Question 1: If a DVIR does not indicate that certain defects have been repaired, and the motor carrier has not certified in writing that such repairs were considered unnecessary, may the driver refuse to operate the motor vehicle? FMCSA-VM-396.13-Q1.cm Prohibition to operate vehicle without certification of repairs
Is there a required form for the periodic inspection? FMCSA-VM-396.17-Q11.cm
Question 4: Is computerized recordkeeping of CMV inspection and maintenance information permissible under § 396.3 of the FMCSRs? FMCSA-VM-396.3-Q004 Vehicle inspection, repair and maintenance
What types of equipment are included in the category of off-road motorized construction equipment? FMCSA-RG-390.5T-Q008 Meaning of “off-road motorized construction equipment”
If a driver commits a felony while operating a CMV but not in the employ of a motor carrier, is the offense disqualifying? FMCSA-DQ-391.15-Q009 Driver disqualification