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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 constitutes a “serious pattern” of violations? FMCSA-RG-390-SPECIALTOPICS-Q01 What is a “serious pattern” of violations?
§391.11 General qualifications of drivers. FMCSA-DQ-391.11-Q003 General driver qualifications
Are trailers which are stacked upon each other and drawn by a motor vehicle by attachment to the bottom trailer, a driveaway-towaway operation. FMCSA-RG-390.5T-Q024 Stacked trailers in driveaway-towaway operations
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
Are trailers which are stacked upon each other and drawn by a motor vehicle by attachment to the bottom trailer, a driveaway-towaway operation? FMCSA-RG-390.5T-Q024 Stacked trailers in driveaway-towaway operations
Question 13: Can random testing be substituted for required follow-up testing? FMCSA-D&A-382.605-Q13 Drug & Alcohol Testing – Random Testing in Lieu of Follow-up Testing
Is the driver required to record meal and other routine stops as off-duty time, or is it the driver’s decision whether such time is recorded as off-duty? FMCSA-HOS-395.2-Q03 Hours of Service Definitions
Is the low pressure warning device required to activate before the tractor protection valve? FMCSA-VEH-393.51-Q01 Must the low-pressure warning device activate before the tractor protection valve?
Do school buses which meet the school bus emergency exit requirements established by NHTSA’s November 2, 1992, final rule on FMVSS No. 217 have to be retrofitted with additional emergency exits when used in interstate commerce for non-school bus operation FMCSA-VEH-393.62-Q03 Must school bus emergency exits be retrofitted for non-school operations?
May tires be filled with materials other than air (e.g., silicone, polyurethane)? FMCSA-VEH-393.75-Q03 Filling tires with material other than air