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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: 16506
16-1289 (GM hazard innovative) -- 28 Apr 16 rsy
Dear Mr. Latouf,   This responds to your letter dated March 18, 2016 requesting an interpretation with respect to the meaning of ?vehicle hazard warning signal operating unit? in Federal Motor Vehicle Safety Standard (?FMVSS?) No. 108; Lamps, reflective devices, and associated equipment, as applied to a new cruise control system General Motors (?GM?) is developing.   You state that GM is developing a new adaptive cruise control system with lane following (which GM has referred to as ?Super Cruise?) that controls steering, braking, and acceleration in certain freeway environments.  When Super Cruise is in use, the driver must always ... Nov 18, 2016

14-001678 IMMI STAR crs
Dear Mr. Vits:   This responds to your letter asking whether your ?STAR? child restraint system is a ?harness? under Federal Motor Vehicle Safety Standard (FMVSS) No. 213, ?Child restraint systems.?  The answer is no.   You describe the STAR as a ?hybrid design of both harness and child seat? made exclusively for school bus use.  The STAR has a five-point webbing system and also a ?lower base booster structure.?[1]  In your letter, you state that the STAR uses?   a booster seating structure that is used to tie in the cam wrap for seat back mount and the five ... Sep 21, 2016

16-002814 Chrysler_VIN_interp_clean_1
Dear Mr. Czapp,   This responds to your letter requesting an interpretation as to whether you may locate the vehicle identification number (VIN) plate on a vehicle?s A-pillar.  Based on the information you have provided, the National Highway Traffic Safety Administration (NHTSA) believes motor vehicle manufacturers are able to locate VIN plates on the A-pillar and comply with the agency?s VIN regulations.    In your letter to NHTSA, you stated that Fiat Chrysler Automobiles (Fiat Chrysler) is considering relocating the VIN plate from the vehicle?s dashboard to the interior portion of the vehicle?s A-pillar.  In further correspondence with Ryan Hagen ... Sep 21, 2016

16-000745 Twisted Restorations revised
Dear Mr. Robinson:   This responds to your February 12, 2016 letter describing your interest in importing Land Rover Defender vehicles that are more than 25 years old into the United States (U.S.) and then ?restoring and modifying? these vehicles in U.S. facilities before selling them.  Your letter describes ?basic? and ?beyond basic? levels of modification and asks if the modifications are so substantial as to be considered a manufacture of ?new? motor vehicles.  You also ask about the Low Volume Motor Vehicle Manufacturers Act of 2015.    As explained in detail below, overall we find that both levels of ... Jul 8, 2016

16-002006 Cybersecurity Act of 2015
Dear Mr. Whitfield:   This responds to your April 2, 2016 letter asking whether the National Highway Traffic Safety Administration (NHTSA) is precluded from taking enforcement action regarding a safety defect or noncompliance with a regulation or Federal Motor Vehicle Safety Standard (FMVSS) when that defect or noncompliance is a cyber threat indicator provided to the Federal government under the Cybersecurity Act of 2015.   As you know, the agency published a request for comments on NHTSA Enforcement Guidance Bulletin 2016-02: Safety-Related Defects and Emerging Automotive Technologies.[1]  We noticed that you submitted identical questions as a comment to the abovementioned ... Jun 1, 2016

ES16-001603 Listou Trailer Response
Dear Mr. Listou:   Thank you for your letter to the National Highway Traffic Safety Administration (NHTSA) asking about NHTSA?s requirements for a trailer and hitch design you invented and for which, you state, you have submitted a provisional patent.  Senator Mark R. Warner has also contacted us on your behalf.  I am pleased to respond.   You state in your letter that you have invented a concept for ?a trailer designed for hauling household trash? that residents in rural areas can use to carry trash to a designated location.  According to your letter, the product would be a collapsible ... May 4, 2016

571.226--modified roof--RVIA--15-006086
Dear Mr. Coon: This responds to your letter asking about the meaning of the term ?modified roof? in S3 of Federal Motor Vehicle Safety Standard (FMVSS) No. 226, ?Ejection mitigation.?  The term is used in FMVSS No. 226 for purposes of determining the applicability of the standard, as ?modified roof vehicles? are excluded from the standard (see S2, FMVSS No. 226).  Your question relates to what you describe as ?light motorhomes weighing less than 10,000 pounds (approximately 2,000 manufactured each year, in the aggregate).?  You describe various ways the roofs of these vehicles are modified by final-stage manufacturers[1] and ask ... Mar 22, 2016

Full Display Mirror System 1 GM Feb 11
Dear Mr. Latouf:   Thank you for your letter informing us about the new Full Display Mirror system that your company plans to install inside a passenger car model, the 2016 MY Cadillac CT6.  I want to thank you especially for the initiative your company took in engaging with this agency?s staff regarding your mirror system.  The National Highway Traffic Safety Administration (NHTSA) seeks to facilitate innovative safety technologies.  This type of exchange between your company and NHTSA about new technologies is an example of how we can work toward improving vehicle safety.   Although your letter did not expressly ... Feb 22, 2016

Google -- compiled response to 12 Nov 15 interp request -- 4 Feb 16 final
Dear Dr. Urmson:   This responds to your November 12, 2015 letter[1] requesting that the National Highway Traffic Safety Administration (NHTSA) interpret a number of provisions in the Federal Motor Vehicle Safety Standards (FMVSSs) as they apply to Google?s described design for motor vehicles that it is in the process of developing and testing.  According to Google, those self-driving vehicles (SDVs) are ?fully autonomous motor vehicles, i.e., vehicles whose operations are controlled exclusively by a Self-Driving System (SDS).?  The SDS is an artificial-intelligence (AI) ?driver,? which is a computer designed into the motor vehicle itself that controls all aspects of ... Feb 4, 2016

15-005347 BMW Brake Transmission Shift Interlock v5
Dear Mr. Campbell:   This responds to your October 5, 2015 letter asking whether BMW?s Park Assistant Plus system complies with the brake transmission shift interlock requirement in Federal Motor Vehicle Safety Standard (FMVSS) No. 114.[1]     Your letter describes your Park Assistant Plus system as a ?remote-controlled parking system? that the driver operates from a location outside, but within six feet of, the vehicle.  You emphasize that BMW?s Park Assistant Plus system is used for only low-speed, short-distance parking maneuvers.  Your letter also indicates the procedure the driver must follow to activate and use the system.   The ... Jan 4, 2016


Dear Mr. Mills:   This responds to your letter, dated April 8, 2011, asking whether the motorcycle rear lamp system you describe is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 108, which governs lamps, reflective devices, and associated equipment on vehicles.  In a February 2012, meeting with agency staff you stated that the project for which you were requesting this  interpretation was on hold.  On October 5, 2015, you emailed Thomas Healy of my staff asking about the status of our response to your letter.  I apologize for the delay in our response.  As explained below, we believe ... Oct 20, 2015

30122 - Make inoperative - Alan Nappier april 14
Dear Mr. Nappier: This responds to your letter asking whether Federal law requires repair shops to repair vehicles using only parts provided by an original equipment manufacturer (OEM) and not ?aftermarket? parts.  You enclosed a December 2010 ?collision repair information? bulletin from Toyota which states that repairing a vehicle using OEM parts and procedures ?can help return Toyota vehicles to pre-loss condition following a collision.?  The bulletin states that Toyota vehicles are ?engineered and manufactured as an integrated assembly of carefully designed and manufactured parts? and that Toyota does ?not recommend the use of alternative parts for the repair of ... Apr 17, 2015

Part 574- TIN font - Weinstein-Continental
Dear Mr. Weinstein:   This letter responds to your request on behalf of Continental AG and its affiliate companies (Continental) for approval of the use of the G006 print type in tire identification numbers, pursuant to Note 3 of Figure 1 in 49 CFR 574.5.  NHTSA is granting your request.   Note 1 of Figure 1 of 49 CFR 574.5 states that the tire identification number, which must appear on every new and retreaded tire, will be in the following fonts:  ??Futura Bold, Modified Condensed? or ?Gothic.??  However, Note 3 states that other print types will be permitted if approved ... Dec 19, 2014

571-213--Graco armrest
Dear Ms. Jones:   This responds to your November 29, 2012 letter to the National Highway Traffic Safety Administration (NHTSA) on behalf of Graco Children?s Products, Inc. (Graco), asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 213, Child restraint systems.  On January 8, 2013, you and Graco representatives met with NHTSA staff to elaborate on the information provided in your letter.     Your questions relate to a Graco belt-positioning booster seat that has armrests that are height-adjustable so that a caregiver can lower or raise the armrests to a height comfortable for the child.  You note Graco has ... May 28, 2014

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


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

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

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

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

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

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

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

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

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

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