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NHTSA's Interpretation Files Search
NHTSA's Chief Counsel interprets the statutes that the agency administers and the regulations that it promulgates. When members of the public ask the agency a question about motor vehicles or motor vehicle equipment that involves these statutes and regulations, the Chief Counsel responds with a letter of interpretation that looks at the particular facts presented in the question and explains how the law applies given those facts. These letters of interpretation, signed by the Chief Counsel, represent the opinion of the agency on the questions addressed at the time of signature and may be helpful in determining how the agency might answer a question that you have if that question is similar to a previously-considered question. Please remember, however, that interpretation letters represent the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. Do not assume that a prior interpretation will necessarily apply to your situation! There are a number of reasons why the interpretation letters in this database might not be applicable to your situation. For more information, see the item below, "How do I use letters of interpretation?"

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Results: 16487
[1] Part 579--EWR--Alliance
Dear Mr. Strassburger:   This responds to your November 6, 2013 letter on behalf of the Alliance of Automobile Manufacturers (Alliance) requesting clarification and guidance regarding a recent amendment to the Early Warning Reporting (EWR) regulation, as set forth in 49 CFR Part 579, subpart C.  Specifically, you seek clarification regarding the updating of manufacturer reports when required to provide updates under 49 CFR 579.28(f)(2)(i)  & (ii).   As background, the EWR regulation requires motor vehicle and equipment manufacturers to submit quarterly reports of early warning information:   production information; information on incidents involving death or injury; aggregate data on property ... Mar 12, 2014

[2] 571-110 placard
Dear Mr. Sisskind:   This letter responds to an email from Clint Hightower of the California Highway Patrol to Louis Molino requesting a written interpretation concerning the definition of the term ?occupant,? as used in Federal Motor Vehicle Safety Standard (FMVSS) No. 110.  Specifically, you would like to know whether the driver is considered an ?occupant? for the purpose of the vehicle placard required by S4.3.  To respond to your question, we would consider the driver to be an ?occupant? of a vehicle for the purpose of stating the vehicle?s seating capacity on the placard required by FMVSS No. 110. ... Feb 4, 2014

[3] 571.213 car seat hook Allen.htm
Dear Ms. Allen:   This responds to your May 17, 2013, letter asking about safety regulations for a device you call a ?car seat hook.?  You explain that the device is used to make it easier for a consumer ?to secure a toddler?s car seat.?  You ask if the product has to be ?crashed tested.?  This letter explains the requirements of the National Highway Traffic Safety Administration (NHTSA) that apply to your product.  The device is not required to be crash tested.   We understand from your letter and the sample product you sent that the car seat hook is ... Oct 30, 2013

[4] 571-208 low rick deployment-Toyota
Dear Mr. Ro:   This letter responds to Toyota?s request for an interpretation of the requirements associated with advanced air bags equipped with multistage inflators.  You state Toyota?s belief that the term ?multistage inflator,? as used in Federal Motor Vehicle Safety Standard (FMVSS) No. 208, Occupant Crash Protection, is not intended to be design-restrictive, but intended to characterize various designs of advanced air bags with decision-based deployment strategies that result in different levels of air bag internal pressure.  You request NHTSA?s confirmation that technologies that are other than or in addition to the types of technologies traditionally used as multistage ... Sep 20, 2013

[5] 571-108 backup lamps of trucks tractor cab
Dear Mr. Siddall:   This is in response to your letter received October 24, 2011 inquiring if backup lamps located on the back wall of the truck tractor cab or sleeper rather than at the standard location, the end of the vehicle, would comply with Federal Motor Vehicle Safety Standard  No. 108, Lamps, Reflective Devices, and Associated Equipment (FMVSS No. 108).  Based on the information you have provided, the placement you describe is not ?on the rear? within the meaning of FMVSS No. 108, and therefore does not comply with our requirements for backup lamps.  We address this question in ... Sep 9, 2013

[6] 571-111  Driver Mirror Flat or Convex  Magna Mirrors  13-001216
Dear Dr. Lynam:   This responds to your letter, dated March 5, 2013, requesting clarification on Federal Motor Vehicle Safety Standard (FMVSS) No. 111, Rearview Mirrors, as it pertains to the driver?s side outside rearview mirror of a passenger car.   Your letter asks whether FMVSS No. 111 permits the use of a ?convex mirror having a radius of curvature of thirty (30) meters and a magnification of 0.95 as the driver?s side outside rearview mirror on a passenger car.?  Your letter also requests that, for purposes of providing an interpretation, NHTSA assume that that the mirror?s field of view ... Aug 15, 2013

[7] Alliance Letter - Sale of Electronic Odometer Resetting Devices
Dear Mr. Strassburger: This letter is in reference to an April 9, 2013 conference call you had with David Sparks of the National Highway Traffic Safety Administration (NHTSA).  During that conference call, you requested NHTSA?s view on the legality of devices that have appeared for sale on the internet that purport to change the mileage showing on electronic odometers of motor vehicles.  These are essentially hand-held devices that connect directly with a vehicle?s on-board computer system through the vehicle?s diagnostic port and provide the user the ability to change the mileage displayed on the vehicle?s electronic odometer.  In the Agency?s ... Aug 7, 2013

[8] Warning letter re electronic devices (Prospeedo)
Dear Mr. Bitz:   The National Highway Traffic Safety Administration (?NHTSA?) is actively investigating potential violations of Federal odometer law.    Federal law prohibits the marketing for sale and sale of devices that are capable of accessing a motor vehicle?s computer system to alter the mileage displayed on the vehicle?s odometer.  These devices make odometers register a mileage different from the mileage the vehicle was driven, whether or not the device is actually used to do so, and thus their marketing and sale violates the prohibition.  Pursuant to 49 U.S.C. § 32703: ?A person may not?(1) advertise for sale, sell, ... Aug 6, 2013

[9] 571-108 -- LED headlamps motorcycles -- Stanley Electric Co. -- 11-006845
Dear Mr. Hasegawa:   This letter is in response to your October 17, 2011 letter inquiring whether certain light-emitting diode (LED) headlamp configurations installed on motorcycles would comply with Federal Motor Vehicle Safety Standard  No. 108, Lamps, Reflective Devices, and Associated Equipment.  We apologize for the delay in our response.  Below we explain how our lighting regulations apply to LED headlamps installed on motorcycles.   By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment (see ... Apr 8, 2013

[10] 571-3 -- multifunction school activity buses -- Georgia Dept of Public Health -- 12-005387
Dear Ms. Conrad:   This responds to your email dated October, 2012 and subsequent conversations with staff of the National Highway Traffic Safety Administration (NHTSA), requesting clarification of NHTSA?s requirements regarding the buses used by ?childcare centers? to transport children to various locations.  You explained to Analiese Marchesseault of my staff that some Georgia childcare centers provide transportation services from the children?s homes to the childcare center only, while some provide transportation from home, the childcare center (for before- or after-school care), and school.  You asked specifically about the use of multifunction school activity buses (MFSABs) in these situations.   ... Feb 28, 2013

[11] 571-201 -- security partitions -- Crowell -- 12-005534
Dear Mr. Crowell:   This responds to your letters to Administrator David Strickland, former Deputy Administrator Ronald Medford, and several other officials of the National Highway Traffic Safety Administration (NHTSA), which we received in October of 2012.  Your letters have been referred to my office for reply.  You ask for help ?correcting the violations found in automobile interior partition performance? in police cruisers, limousines, utility vans, and taxicabs.  The partitions separate the front seat occupants (particularly the driver) from back seat passengers, primarily for security reasons.  I will refer to these as ?security partitions.?   From the enclosures you sent, ... Jan 11, 2013

[12] Mr. Steven A. Bennett
Dear Mr. Bennett:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[13] Ms.Patricia R. Hatler
Dear Ms. Hatler:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[14] Mr. Jeffrey W. Jackson
Dear Mr. Jackson:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[15] Mr.Charles E. Jarrett
Dear Mr. Jarrett:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[16] Ms.Susan L. Lees
Dear Ms. Lees:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[17] Mr. Christopher C. Mansfield
Dear Mr. Mansfield:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[18] Mr.Garrett Paddor
Dear Mr. Paddor:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.       We understand that when a flood-damaged vehicle is declared a ... Dec 20, 2012

[19] Mr. Dana Proulx
Dear Mr. Proulx:   We have received reports that certain insurance companies may be engaging in transactions that violate Federal odometer disclosure law with respect to vehicles damaged in Hurricane Sandy.  Although we are not asserting that your company is engaging in such practices, we are writing to a number of auto insurance companies to remind them of the Federal odometer disclosure law requirements and ask them to review their practices regarding odometer disclosures.  These letters do not accuse your company, or any other company, of violating the law.        We understand that when a flood-damaged vehicle is declared ... Dec 20, 2012

[20] ITA_Defective_Tire_Exportation_12-00245
Dear Ms. Wilson:               This letter responds to your January 19, 2012 letter on behalf of ITR USA, Inc. requesting an interpretation of certain provisions of the Transportation Recall Enhancement, Accountability, and Documentation Act, Pub. L. No. 106-414, 114 Stat. 1800 et. seq. (2000) (TREAD Act).  You ask for clarification regarding two requirements under the TREAD Act:  the requirement in Section 7 that directs tire manufacturers, which includes importers, conducting recalls to include in their remedy program plans addressing how to prevent replaced tires from being resold for installation on a motor vehicle and the prohibition in Section 8 ... Oct 3, 2012

[21] 11-007173_R_Kesler_(Std 111)_Rearview_Mirrors
Dear Mr. Kesler:   This responds to two letters the agency has received from you dated September 7, 2011 and May 10, 2012, concerning your product: the Lane Change Safe Alert Indicator.  In both of your letters, you describe your product in detail and various situations where you believe the product would be helpful to a driver conducting a lane change maneuver.  As you describe in those letters, your Lane Change Safe Alert Indicator product utilizes modified OEM convex mirrors that have the alert indicators permanently inscribed on the mirror for both driver and passenger sides.  Further, the mirror contains ... Sep 25, 2012

[22] 12-001952 Matheny capacity includes driver (Standard No. 217)
Dear Mr. Fowler:               This responds to your letter to the National Highway Traffic Safety Administration (NHTSA) asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 217, ?Bus Emergency Exits and Window Retention and Release.?  We apologize for the delay in responding; we regret that we did not receive the January 19, 2012 letter you had sent.               You ask for clarification of the term ?seating capacity? as used in Table 1 and Table 2 of FMVSS No. 217, i.e., whether the driver is considered part of the ?seating capacity? of a bus for purposes of determining the ... Aug 14, 2012

[23] 12-003091 Giordano (Std. No 120)
Dear Mr. Giordano:   This letter responds to your request for clarification regarding the relationship between the certification label and the tire selection requirements for school buses with a gross vehicle weight rating (GVWR) of more than 10,000 pounds under Federal Motor Vehicle Safety Standard (FMVSS) No. 120, which relates to tire selection and rims.  We are pleased to provide the following clarification.   We begin by clarifying NHTSA?s regulatory authority.  NHTSA has the authority under 49 U.S.C. Chapter 301 to prescribe Federal motor vehicle safety standards (FMVSSs).  The FMVSSs are applicable to new motor vehicles and new motor vehicle ... Aug 10, 2012

[24] 11-000612 M.Edie (Part 523)
Dear Mr. Edie: This is a response to your letter on January 21, 2011, in which you requested an interpretation of 49 CFR 523.2 and 523.5(b)(2) as they would apply to the classification of a motor vehicle with components affixed to its undercarriage.  The specific components described in your letter are tire aero deflectors, which are attached in front of the tires in order to reduce aerodynamic drag and thereby improve fuel economy.  Your letter states that in order to perform as needed, some of the components may be between 20 and 15 centimeters from their lowest point to the ... Jul 30, 2012

[25] DNBA_B.Nicolle_Parts_573_and_579
Dear Mr. Nicolle,   Thank you for your email of June 1, 2012 requesting a written notification of the legal obligations of Daimler Buses North America (DBNA) in light of the planned changes at DBNA.   You state that DBNA has decided to cease manufacturing and outfitting buses in North America, and explain that this will affect Orion, Sprinter, and Setra buses and motorcoaches.  You also state that DBNA will maintain a presence to handle service, warranty, and replacement parts issues for Orion buses, and that Setra will be ?transferred? to MCI Corporation for sales marketing, service and warranty issues.  ... Jul 19, 2012