NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date |
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ID: nht94-8.18OpenDATE: February 14, 1994 FROM: March, Gary D. -- Director, Illinois Department Of Transportation, Division Of Traffic Safety TO: Womack, John -- Acting Chief Counsel, NHTSA TITLE: Docket No. 88-21; Notice No. 3 57 FR 49413, November 2, 1992 ATTACHMT: Attached To 10/01/94 (EST.) Letter From John Womack To Gary D. March (A42; STD. 217; Part 586) TEXT: On November 2, 1992, NHTSA published a Final Rule which revised the minimum requirements for school bus emergency exits and improved access to school bus emergency doors. I am sure you would agree that the purpose of this rulemaking was to enhance the safety of children being transported in school buses. The Docket states that this Final Rule is effective May 2, 1994. We at the Illinois Department of Transportation interpret this Docket to mean school buses manufactured on or after May 2, 1994 must comply with these new standards. In September of 1993, we were asked the following question by a school bus distributor here in Illinois: Does the vehicle's "date of manufacture" correspond to the vehicle's chassis completion date or the vehicle's body completion date? In essence, he asked when do manufacturers have to comply with this Docket? On September 27, 1993, Ms. Catherine Allen of my staff spoke to Mr. David Elias of NHTSA and asked him the above question. He indicated the date of manufacture is correlated to the vehicle's date of completion. The vehicle's date of completion corresponds to the date when the body and chassis are combined to form a completed vehicle. Therefore, we interpreted that answer to mean vehicles "combined" on or after May 2, 1994 must comply with this Docket. On February 2, 1994, Ms. Allen spoke to Ms. Jane Dawson of Thomas Built Buses and asked if school buses manufactured on or after May 2, 1994 would meet the new standards. She replied, "Only if the chassis was manufactured on or after May 2, 1994." She indicated multi-stage manufacturers have the option of choosing the chassis manufacture date, the body manufacture date or a date in-between for the effective date of new standards. On February 3, 1994, Ms. Allen spoke to Mr. Charles Hott of NHTSA and asked him the same question. He confirmed what Ms. Dawson had said. Therefore, according to Mr. Hott's interpretation, a school bus which clearly displays a June 1994, or later, date of manufacture will not need to meet the standards of Docket 88-21 if the chassis was completed prior to May 2, 1994. Since we have received two different interpretations from Mr. Elias and Mr. Hott, we are asking for an official interpretation from the agency. Currently, school districts are in the process of taking bids on buses that will be delivered and perhaps have bodies mounted after May 2, 1994 to chassis manufactured prior to May 2, 1994. Therefore, I am sure you can understand the necessity of a prompt and official interpretation by your office. If you need any additional information from us, please contact Mr. Larry Wort at 217/782-4974 or Ms. Catherine Allen at 217/785-1181. I will appreciate your expeditious response. |
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ID: nht94-8.19OpenDATE: February 11, 1994 FROM: Jerry L. Steffy -- Triumph Designs, Ltd. TO: Taylor Vinson -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 3/16/94 from John Womack to Jerry L. Steffy (A42; Std. 108; Part 555) TEXT: Since I faxed you with my question regarding FMVSS 108 and ECE Reg. 20, I received Part 555 of 49 CFR from Luke Loy. 555.5 implies that we could apply for an exemption from FMVSS 108 for this headlamp since there exists "an equivalent overall level of motor vehicle safety." This is of course, if NHTSA recognizes the worthiness of the testing under ECE Reg. 20. This exemption would only be for the first model year as afterwards we will change to a headlamp already FMVSS 108. Can you please confirm for the if this is a route we can employ in this instance? Best regards. 2-10-94 fax from J.L. Steffy to Taylor Vinson: Dear Taylor: Luke Loy suggested that I contact you with a specific query I have. Recently, in Canada, we were able to use ECE Reg. 20 in lieu of FMVSS 108 for a particular headlamp system use. Is it possible to substitute ECE 20 for FMVSS 108 in the states in some instances? Of course the majority of our suppliers fulfill testing according to FMVSS 108 however, there are individual exceptions. Some cases may require significant investment in order to have individual cases comply, so it is important to know. Best regards |
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ID: nht94-8.2OpenDATE: March 7, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Lawrence A. Beyer TITLE: None ATTACHMT: Attached to letter dated 2/14/94 from Lawrence A. Beyer to Z. Taylor Vinson (OCC-9662) TEXT: This responds to your FAX of February 14, 1994, to Taylor Vinson of this Office regarding the "re-importation" of used certified motorcycles into the United States after modifications have been performed abroad. These modifications would not involve a "knowingly rendering inoperative" of equipment related to the Federal motor vehicle safety standards. You have asked whether our interpretation of November 16, 1992, "regarding this matter" remains operative. We assume the letter to which you refer is the one addressed to Wolfgang Klamp of Blaine, Washington. Mr. Klamp's wife crossed the border daily in her Canadian-manufactured Ford Tempo to her Canadian place of employment. Because the vehicle was not certified as meeting U.S. safety standards, the U.S. Customs Service had informed her the car would not be admitted in the future without going through the formal entry process for conversion to the U.S. standards. We verified that the Customs Service was acting in accordance with the National Traffic and Motor Vehicle Safety Act, and provided several suggestions. This letter remains our position. However, we fail to understand its relevance to the fact situation you present regarding importation of motorcycles that are certified as meeting the Federal motor vehicle safety standards. We can only surmise that individual Customs officials may be questioning whether the modified motorcycles comply with all applicable U.S. Federal motor vehicle safety standards at the time of entry, notwithstanding the fact that they are certified as complying as of their manufacture. As you know, a motor vehicle offered for importation must comply with the U.S. safety standards at the time of importation (or be converted to those standards after entry), regardless of its state of compliance at the time of its manufacture. We have no regulations under which a manufacturer, distributor, dealer, or motor vehicle repair business may state that it has not knowingly rendered inoperative any device or element of design installed in accordance with a Federal motor vehicle safety standard. However, we would recommend that Customs accept such a statement accompanying an HS-7 Form's declaration of vehicle compliance if it also contained the statement that in the modifier's opinion the vehicle remained in compliance upon completion of the modifications. Alternatively, and relevant to modifications that relate to a safety standard which may not have had to be met initially (i.e. installation of glazing on a motorcycle that was not originally manufactured with a windshield), we suggest that the modifier provide a statement, in writing or on a label affixed to the vehicle, of the kind required of an alterer of a new vehicle, as set forth in 49 CFR 567.7. This statement attests to the continuing compliance of a motor vehicle after modification. Our willingness to accept such a statement should enable Customs to enter the modified motorcycles as conforming vehicles. |
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ID: nht94-8.20OpenDATE: February 10, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: David Shapiro -- RV Designer Collection, Woodbridge, Inc. TITLE: None ATTACHMT: Attached to letter dated 11/17/93 from David Shapiro to NHTSA Chief Counsel (OCC-9358) TEXT: This responds to your inquiry about the applicability of Standard No. 302, Flammability of Interior Materials to aftermarket products. You state that you are planning to market fabric window coverings such as drapes and fabric bedding such as bedspreads for use in recreational vehicles. In response to your request for confirmation that Standard No. 302 does not apply to aftermarket products, I am pleased to have this opportunity to explain our regulations to you. By way of background information, NHTSA is authorized to issue Federal Motor Vehicle Safety Standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests new vehicles and items of equipment for compliance with the standards. In response to your question, there are currently no Federal motor vehicle safety standards (FMVSS's) that directly apply to the products you wish to manufacture. Under the authority of the Safety Act, NHTSA has issued Standard No. 302, which specifies requirements for the flammability resistance of materials in the occupant compartment of new vehicles. However, Standard No. 302 would not apply to your products because that standard applies to new motor vehicles and not to aftermarket items of motor vehicle equipment. I note, however, that there are other Federal requirements that indirectly affect the manufacture and sale of your products. Under the Safety Act, your products are considered to be items of motor vehicle equipment. As a manufacturer of motor vehicle equipment, you are subject to the requirements in S151-159 of the Safety Act concerning the recall and remedy of products with safety related defects. I have enclosed an information sheet that briefly describes those responsibilities. In the event that you or NHTSA determines that your products contain a safety-related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. I note that even though Standard No. 302 would not apply to your product, the product's flammability characteristics could be relevant to whether it contained a safety related defect. Manufacturers, distributors, dealers, and motor vehicle repair businesses are subject to S108(a)(2)(A) of the Safety Act, which states: "No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative...any vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard...." This section would prohibit any manufacturer, distributor, dealer, or repair business from installing your product in used vehicles if the effect of such installation was to render inoperative the compliance of the vehicle with any safety standard, including Standard No. 302. The "render inoperative" prohibition of S108(a)(2)(A) does not apply to the actions of vehicle owners in adding to or otherwise modifying their vehicles or items of motor vehicle equipment. Thus, if your products were placed in vehicles by the vehicle owners, your products would not need to meet any FMVSSs. Nevertheless, in the interest of safety, we suggest you consider conforming your product to a flammability resistance standard equivalent to Standard No. 302. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. |
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ID: nht94-8.21OpenDATE: February 10, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Pat McCue -- Allied Service Systems Manufacturing TITLE: None ATTACHMT: Attached to letter dated 7/15/93 from Pat McCue to Ed Jettner (OCC-8962) TEXT: This responds to your letter to Mr. Ed Jettner of this agency concerning an occupant restraint system you have developed to protect medics and attendants in the back of ambulances. I apologize for the delay in our response. The system consists of a vest worn by the attendant which is attached by a tether strap to the ambulance. During an August 23, 1993 phone call with Mary Versailles of my staff, you explained that the tether straps include retractors which lock during a crash. During this phone call you also stated that the back vest can be attached to two tethers on the vehicle wall adjacent to the bench seat, and that the front of the vest is attached to another tether on the opposite wall. You asked for advice on "how regulations are established and how products are tested to meet standards." The National Traffic and Motor Vehicle Safety Act (the Safety Act) authorizes this agency to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment is in conformity with all applicable safety standards. NHTSA does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA has exercised its authority to establish three safety standards that may be relevant to a vest and tether system for ambulance attendants. The first is Standard No. 208, Occupant Crash Protection, which sets forth requirements for occupant protection at the various seating positions in vehicles. Ambulances, which are classified as multipurpose passenger vehicles under our regulations, are required to have safety belts at each designated seating position. The second relevant standard is Standard No. 302, Flammability of Interior Materials. This standard specifies burn resistance requirements for materials used in the occupant compartment of motor vehicles, including ambulances. The third relevant safety standard is Standard No. 209, Seat Belt Assemblies, which sets forth strength, elongation, webbing width, durability, and other requirements for seat belt assemblies. Standards No. 208 and No. 302 apply, with certain exceptions that are not relevant to your product, to vehicles and not directly to items of equipment. Thus, the vehicle manufacturer, and not the equipment manufacturer, is responsible for certifying compliance to these standards. Standard No. 209, however, applies to seat belt assemblies as separate items of motor vehicle equipment, regardless of whether the belts are installed as original equipment in a motor vehicle or sold as replacements. Standard No. 209 defines a "seat belt assembly" as "any strap, webbing, or similar device designed to secure a person in a motor vehicle in order to mitigate the results of any accident, including all necessary buckles and other fasteners, and all hardware designed for installing such seat belt assembly in a motor vehicle." Thus, your vest and tether system would be considered a "seat belt assembly," and the manufacturer of the system would be required to certify that it complies with Standard No. 209 before it could be sold. If the vest and tether system was installed as original equipment by the vehicle manufacturer, the vehicle manufacturer would be required to certify that the vehicle complied with all applicable safety standards with that equipment installed in the vehicle. If the device was added to a new ambulance prior to its first sale, e.g., by the dealer, the person who modified the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. I note that in your phone conversation with Ms. Versailles, you stated that your ambulances do have safety belts on the bench seat, however, these do not provide the mobility needed by the attendants when they are caring for a patient. It is our understanding that you intend the vest and tether system to supplement the original safety belts. If your vest and tether system were installed in addition to the safety belts required by Standard No. 208, and provided that the installation did not interfere with the required safety belts, such installation would not affect the compliance of the vehicle with Standard No. 208, since the standard's requirements would be fully met by the original belts. After the first purchase of a vehicle for purposes other than resale, the only provision in Federal law that affects the vehicle's continuing compliance with an applicable safety standard is set forth in section 108(a)(2)(A) of the Safety Act. That section provides that: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard. This provision would prohibit any of the named commercial entities from installing your system if such installation rendered inoperative the compliance of the vehicle with any applicable safety standard. For example, if the material used in your system did not meet the burn resistance requirements of Standard No. 302, installation of the system would render inoperative compliance with that standard. The render inoperative provision does not prohibit owners from modifying their vehicles, even if such modification adversely affects the compliance of the vehicle with safety standards. However, this agency encourages vehicle owners not to make any modifications which would negatively affect the occupant protection systems installed in their vehicles. Also, vehicle modifications by owners may be regulated by state law. In addition to certifying that your vest and tether system complies with Standard No. 209, I urge you to exercise care in evaluating how effective this system would be in an actual crash situation. The original belt system supplied with the vehicle limits the motion of the occupant by keeping the occupant attached to the seat. Your system would have a dual purpose: allowing the attendant sufficient mobility to care for a patient and protecting the attendant in a crash. The tether on your system will not achieve this second purpose if it allows too much motion within the compartment. You may wish to consult a private attorney familiar with the law in the State of Arizona regarding potential liability in tort for your business. I also note that every State provides for some degree of civil liability for consumer products and repair work. I have also enclosed an information sheet that identifies relevant Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers, and explains how to obtain copies of these materials. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. |
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ID: nht94-8.22OpenDATE: February 9, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Maurice Hannigan -- Commissioner, Dept. of California Highway Patrol TITLE: None ATTACHMT: Attached to letter dated 8/5/93 from P. J. Harrington to Potter Valley Community Unified School Dist. Superintendent and letter dated 3/31/93 from John Womack to W. C. Burke TEXT: It has come to our attention that a misunderstanding has arisen about a letter we issued on March 31, 1993 to W.C. Burke of your Department. That letter explained the marking responsibilities of a person who installs replacement glass (referred to as glazing in the Federal standard) under section S6.4 of Federal motor vehicle safety standard No. 205, Glazing Materials (49 CFR S571.205, copy enclosed.) On January 12, 1994, Mr. Clarke Harper of this agency's Office of Vehicle Safety Standards and Mr. Marvin Shaw of my staff contacted Mr. Walter Burke and Mr. Kyle Larson of CHP to discuss this matter. This letter is a follow up to that discussion. Based on its understanding of the March 1993 letter, CHP is requiring installers to mark replacement glazing with a number (which the agency refers to as a manufacturer's code mark) and has directed school districts to tell installers of glass to contact NHTSA "(t)o obtain a number as required by (Standard No. 205)." Standard No. 205 does not require the typical aftermarket installer to obtain such a number from the agency. We explained in the March 1993 letter that a person who cuts glazing (i.e., a typical installer of aftermarket glazing) must mark the piece with the following information required by section 6 of American National Standard (ANS) Z26: (1) the words "American National Standard" or the characters "AS," (2) a number identifying the item of glazing, (3) a model number assigned by the manufacturer that identifies the type of construction of the glazing material, and (4) the manufacturer's distinctive designation or trademark. Mr. Larson stated that he was under the impression that "(3) a model number assigned by the manufacturer" was a number assigned by NHTSA. As we explained to him, this is not the case. The installer devises his own model number. The only number assigned by NHTSA under Standard No. 205 is the code mark assigned to a manufacturer who "fabricates, laminates, or tempers the glazing material" (known as a "prime glazing material manufacturer"). We hope that this clarifies our earlier letter on this subject. If you have any other questions, please contact Mr. Shaw at (202) 366-2992. |
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ID: nht94-8.23OpenDATE: February 9, 1994 FROM: James H. Shuff -- President, Freedom Trailers TO: Chief Counsel, NHTSA TITLE: NONE ATTACHMT: Attached to letter dated 7/14/94 from John Womack to James H. Shuff (A42; STD 120; VSA 102(3)) TEXT: I was advised by Mr. George Shifflet of the D.O.T. to contact you and request a ruling on the Park Model Travel Trailers that I am building. I am custom building park model travel trailers. These units, by ANSI code 119.5, are limited to a maximum of 400 sq, ft. There are park models that are recognized by H.U.D. but they are 500sq. ft. They are intended for recreational use only and not for year round living. These units can be used in the same manner as conventional travel trailers for winter camping in the year round parks. These units can be as wide as 12'. The units that I am building are to order only. Once they are constructed they will be towed to their campsite and set up. The tires and the rims will be retained by me and used over again. Mr. Shifflet did not seem to think that there would be a problem with this, but suggested that I contact you for an opinion. |
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ID: nht94-8.24OpenDATE: February 8, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Honorable Sam Nunn -- Chairman, Committee on Armed Services, U. S. Senate TITLE: None ATTACHMT: Attached to letter dated January 11, 1994 from Sam Nunn to Jackie Lowey, letter dated 12/22/94 from Bill Lee to Sam Nunn and letter dated 12/17/93 from Tim Adamson to Bill Lee TEXT: This responds to your letter of January 11, 1994, to the Acting Director of Congressional Affairs, DOT, with respect to an inquiry from Georgia State Representative Bill Lee regarding the disposition of surplus HMMMV (Humvee) military vehicles. The National Highway Traffic Safety Administration (NHTSA) is the component within DOT that establishes and enforces the Federal Motor Vehicle Safety Standards (FMVSS) under the authority of the National Traffic and Motor Vehicle Safety Act of 1966. In recognition of the fact that compliance with the FMVSS could interfere with the ability of a military vehicle to perform its intended task, we have always exempted from compliance with the FMVSS any motor vehicle that is manufactured for, and sold directly to, the Armed Forces of the United States in conformity with contractual specifications. When such a vehicle has reached the end of its useful military life, the question arises as to its proper disposition. NHTSA has no authority over the disposition that any owner wishes to make of his motor vehicle, whether civilian or military in nature, thus the matter is not the subject of any DOT-administered statute or of any NHTSA regulations. From time to time the Department of Defense (DOD) asks our advice on disposal of surplus vehicles; we provide it and DOD appears to follow it. However, in the last analysis, it is DOD's policy that governs the disposal of surplus military motor vehicles. With respect to the HMMMV, we have advised DOD that we deem it not in the interests of traffic safety to sell for civilian use a motor vehicle that is not in compliance with the FMVSS. We recognize that there is a competing public interest in recovery of Federal funds to the extent practicable but, in our view, it is outweighed by the interest in safety. Given the fact that HMMMVs are now available that meet the FMVSS, we have further advised DOD to consult with the HMMMV's manufacturer to determine whether military vehicles might be retrofitted to comply with the FMVSS. If this can be accomplished, NHTSA would have no objection to the sale of retrofitted military HMMMVs for civilian use. I hope that this clarifies the matter for Representative Lee. |
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ID: nht94-8.25OpenDATE: February 8, 1994 FROM: Ilmars Ozols TO: Mr. John Womack -- Acting Chief Council, NHTSA TITLE: None ATTACHMT: Attached To Letter Dated 5/6/94 From John Womack To Ilmars Ozols (A42; VSA 5104(4) TEXT: Dear Sir: As a result of my telephone conversation with one of your associates on February 1, 1994, I am communicating with you and would like to request your assistance to determine if SERV-O-TRAY is in compliance with existing National Highway Traffic and Safety Administration relevant codes and regulations with regards to after market product installation in a motor vehicle. SERV-O-TRAY is a patented folding/adjustable table for vehicles intended to provide comfort for drivers and front seat passengers whether the vehicle is stationary or movement mode. For your information I am enclosing a photograph of SERV-O-TRAY prototype installation in a motor vehicle and SERV-O-TRAY's technical description which hopefully will assist you in your task. If you require additional information, please do not hesitate to contact me at the above address, or telephone (619) 327-8290. Sincerely, |
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ID: nht94-8.26OpenDATE: February 7, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Cheryl Graham -- District Manager, Northeast Region, ARI TITLE: None ATTACHMT: Attached to letter dated 11/10/93 from Cheryl Graham to Chief Counsel's Office, NHTSA (OCC-9345) TEXT: We have received your letter of November 10, 1993, asking about the permissibility of aftermarket installation of an auxiliary pair of stop lamps "at each side of the rear window." by way of background information the National Highway Traffic Safety Administration (NHTSA) issues Federal motor vehicle safety standards under the authority of the National Traffic and Motor Vehicle Safety Act (Safety Act). Under that Act, the sole restraint upon modifications to vehicles in use is that, if performed by a manufacturer, distributor, dealer, or motor vehicle repair business, the modifications must not "knowingly render inoperative, in whole or in part, any device or element of design installed on...a motor vehicle in compliance with an applicable Federal motor vehicle safety standard...." (15 U.S.C. 1397(a)(2)(A)). In NHTSA's view, if the modifications tend to impair the safety effectiveness of the "device or element of design," then, at the minimum, a partial inoperability may have occurred within the meaning of the statutory prohibition. The question raised by your letter, therefore, is whether the installation of the auxiliary stop lamps in that location would impair the effectiveness of the three original equipment stop lamps. NHTSA decided to require the center highmounted stop lamp in addition to the then-existing original equipment two-lamp stop lamp system following research which indicated that a three-lamp system of this configuration was demonstrably more effective in preventing rear end crashes than other rear end lighting systems that were tested, and considerably lower in cost. Included in the testing was a four-lamp system which incorporated two lamps at each side of the rear window, but no tests were conducted on the five-lamp system you describe. The reasons for the better performance of the three-lamp system are unclear, but the triangular lighting array proved to be more effective than the trapezoidal four-lamp system (and more effective than a system tested which separated the usual stop lamp from the tail lamp). Your customer appears to believe that the ability of following drivers to avoid rear end crashes is enhanced by a five-lamp stop lamp system. On the other hand, your proposed system, by incorporating the two lamps at each side of the rear window, would appear to change the lighting array. We cannot say that the five-lamp system would either enhance or detract from safety. Thus, we cannot find that the additional lamps would "render inoperative" the original equipment three-lamp system, and it would be permissible under the regulations of this agency. However, the permissibility of such a modification would be determinable under State law. We are unable to advise you on the laws of the various States and suggest that you write the American Association of Motor Vehicle Administrators for an interpretation. Its address is 4600 Wilson Boulevard, Arlington, VA 22203. You have also asked "if the work is done improperly and results in an accident, where does the liability lie?" This question is a matter of state law, and we suggest that you consult a local attorney concerning it. |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.