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.”
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NHTSA's Interpretation Files Search
| Interpretations | Date |
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ID: nht80-2.31OpenDATE: 05/06/80 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: International Harvester Company TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of April 3, 1980, requesting confirmation of the applicability of S4.4 of Federal Motor Vehicle Safety Standard No. 115 (49 CFR 571.115) solely to light trucks and passenger cars. Although Standard No. 115 applies to a variety of vehicle types, including multipurpose passenger vehicles, the location requirement in S4.4 regarding the placement of the vehicle identification number is of more limited applicability. The section expressly provides that the requirement applies to passenger cars and to trucks with a gross vehicle weight rating (GVWR) of 10,000 pounds or less only. Since Standard No. 115 does not contain any other VIN location requirement, manufacturers of multi-purpose passenger vehicle, buses, trailers, incomplete vehicles, and heavy trucks are not limited by that standard in their choice of a VIN location. For definitions of these vehicle types, see 49 CFR 571.3. Sincerely, ATTACH. April 3, 1980 Frederic Schwartz -- Office of Chief Counsel, National Highway Traffic Safety Administration SUBJECT: Applicability of FMVSS115, S4.4 Dear Mr. Schwartz: This letter will confirm a telephone conversation of February 13, 1980 between Mr. R. C. Hamilton and yourself regarding the applicability of FMVSS 115 paragraph S4.4 to Multi Purpose Vehicles. Mr. Hamilton was advised of the following: S4.4 does not apply to MPV's or vans. Further, the NHTSA had not intended for MPV's or vans to meet the requirement that the VIN be readable through the windshield glass from a point outside the vehicle. As written S4.4 is applicable only to passenger cars and light trucks with a GVWR of 10,000 pounds or less. The above represents our understanding of the applicability of S4.4 of FMVSS 115. Sincerely, INTERNATIONAL HARVESTER COMPANY; F. L. Krall, Manager -- Technical Legislation |
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ID: aiam0029OpenMr. E.L. Koepenick, Secretary-Treasurer, Fire Apparatus Manufacturers Association, Inc., 7979 Old Georgetown Road, Washington, D.C. 20014; Mr. E.L. Koepenick Secretary-Treasurer Fire Apparatus Manufacturers Association Inc. 7979 Old Georgetown Road Washington D.C. 20014; Dear Mr. Koepenick: #Thank you for your letter addressed to Dr. Haddon dated June 19, 1967, which has been referred to me for reply to your inquiry concerning the effect of Motor Vehicle Safety Standards on fire trucks. #The purpose of Standard No. 107 is to reduce the likelihood that unacceptable glare from reflecting surfaces in the driver's field of view will hinder the safe and normal operation of the motor vehicle. At present, paragraph S4, 'Requirements,' only covers windshield wiper arms and blades, inside windshield mouldings(sic), horn rings and hub of the steering wheel, and inside rearview mirror frame and mounting bracket. #The initial Federal Motor Vehicle Safety Standards contain no mandatory requirement for seat belt installations or seat belt anchorages in trucks. However, if seat belts are installed in truck they must conform to Motor Vehicle Safety Standard No. 209, effective March 1, 1967. #Sincerely, George C. Nield, Acting Director, Motor Vehicle Safety Performance Service; |
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ID: 6952Open Mr. Arthur J. Kuminski Dear Mr. Kuminski: This responds to your letter of February 3, 1992 concerning Federal Motor Vehicle Safety Standard No. 206, Door Locks and Door Retention Components. You asked about the standard's test requirements for sliding doors on cargo vans (sections S4.3 and S5.3). Your three questions and the response to each follow. 1. I will need specifications on how to perform this test on a test fixture using the striker assembly and the door latch only. Standard No. 206 "specifies requirements for side door locks and side door retention components including latches, hinges, and other supporting means, to minimize the likelihood of occupants being thrown from the vehicle as a result of impact." The standard's requirements for sliding doors are set forth in sections S4.3 and S5.3. Section S4.3 specifies that the track and slide combination or other supporting means for each sliding door shall not separate when a total transverse load of 4,000 pounds is applied, with the door in the closed position. Section S5.3 states, "(c)ompliance with S4.3 shall be demonstrated by applying an outward transverse load of 2,000 pounds to the load bearing members at the opposite edges of the door (4,000 pounds total). The demonstration may be performed either in the vehicle or with the door retention components in a bench test fixture." Under section S5.3, the same basic procedure is conducted whether the test is conducted in a vehicle or with the door retention components in a bench test fixture, i.e., an outward transverse load of 2,000 pounds is applied to the load bearing members at the opposite edges of the door (4,000 pounds total). The details of the procedure using a bench test fixture will necessarily vary for different designs of sliding doors, since the door retention components themselves vary. The test should be conducted in such a manner that the same loads are applied to the door retention components as would occur in a vehicle test. You specifically asked about how to perform the test on a test fixture using the striker assembly and door latch only. I note that since the requirement in section S4.3 applies to the "track and slide combination or other supporting means" for a sliding door, the striker assembly and door latch of a sliding door are tested only if they are part of the supporting means for the door. I also note that the entire supporting means for a sliding door is tested under section S5.3 and not merely one part. I have enclosed for your information a copy of a May 13, 1975 interpretation letter to Toyota (including the incoming letter) which discusses various demonstration test fixtures which might be used to test sliding doors under Standard No. 206. 2. What load must the system withstand in the primary locked position to pass the test? 3. Is there a load requirement that the system must withstand in the secondary locked position to pass the test? Section S4.1.1 of Standard No. 206 requires hinged doors, other than cargo-type doors to have both a fully latched position and a secondary latched position. There is not a similar requirement for sliding doors. Section S4.3 requires only one test, with a total load of 4,000 pounds, for sliding doors. This test would be performed with the door latched. 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. Sincerely, Paul Jackson Rice Chief Counsel Enclosures ref:206 d:3/30/92 |
1992 |
ID: nht92-8.13OpenDATE: March 30, 1992 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Arthur J. Kuminski -- Design Engineer, Eberhard Manufacturing Co. TITLE: None ATTACHMT: Attached to letter dated 2/3/92 from Arthur J. Kuminski to Paul J. Rice (OCC 6952) TEXT: This responds to your letter of February 3, 1992 concerning Federal Motor Vehicle Safety Standard No. 206, Door Locks and Door Retention Components. You asked about the standard's test requirements for sliding doors on cargo vans (sections S4.3 and S5.3). Your three questions and the response to each follow. 1. I will need specifications on how to perform this test on a test fixture using the striker assembly and the door latch only. Standard No. 206 "specifies requirements for side door locks and side door retention components including latches, hinges, and other supporting means, to minimize the likelihood of occupants being thrown from the vehicle as a result of impact." The standard's requirements for sliding doors are set forth in sections S4.3 and S5.3. Section S4.3 specifies that the track and slide combination or other supporting means for each sliding door shall not separate when a total transverse load of 4,000 pounds is applied, with the door in the closed position. Section S5.3 states, "(c)ompliance with S4.3 shall be demonstrated by applying an outward transverse load of 2,000 pounds to the load bearing members at the opposite edges of the door (4,000 pounds total). The demonstration may be performed either in the vehicle or with the door retention components in a bench test fixture." Under section S5.3, the same basic procedure is conducted whether the test is conducted in a vehicle or with the door retention components in a bench test fixture, i.e., an outward transverse load of 2,000 pounds is applied to the load bearing members at the opposite edges of the door (4,000 pounds total). The details of the procedure using a bench test fixture will necessarily vary for different designs of sliding doors, since the door retention components themselves vary. The test should be conducted in such a manner that the same loads are applied to the door retention components as would occur in a vehicle test. You specifically asked about how to perform the test on a test fixture using the striker assembly and door latch only. I note that since the requirement in section S4.3 applies to the "track and slide combination or other supporting means" for a sliding door, the striker assembly and door latch of a sliding door are tested only if they are part of the supporting means for the door. I also note that the entire supporting means for a sliding door is tested under section S5.3 and not merely one part. I have enclosed for your information a copy of a May 13, 1975 interpretation letter to Toyota (including the incoming letter) which discusses various demonstration test fixtures which might be used to test sliding doors under Standard No. 206. 2. What load must the system withstand in the primary locked position to pass the test? 3. Is there a load requirement that the system must withstand in the secondary locked position to pass the test? Section S4.1.1 of Standard No. 206 requires hinged doors, other than cargo-type doors to have both a fully latched position and a secondary latched position. There is not a similar requirement for sliding doors. Section S4.3 requires only one test, with a total load of 4,000 pounds, for sliding doors. This test would be performed with the door latched. 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: nht68-4.17OpenDATE: 09/17/68 FROM: AUTHOR UNAVAILABLE; William Haddon, Jr.; NHTSA TO: Chrysler Corporation TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of September 11, 1968, to Mr. J.E. Leysath of this Bureau, concerning the Chrysler Super Lite which you intend to offer as an optional supplemental light on some of the Chrysler 1969 car lines. You are correct in your understanding that a supplemental light of this type is not required by Federal Motor Vehicle Safety Standard No. 108. Standard No. 108 does, however, specify, in Paragraph S3.1.2, that no additional lamp, reflective device, or associated equipmont shall be installed if it impairs the effectiveness of the required equipment. On the basis of our review of your technical literature on the Super Lite and our observation of limited field demonstrations of the light, it does not appear that the Super Lite will impair the effectiveness of the lighting equipment required by Standard No. 108. It should be noted, however, that, while the incorporation of this lamp in your 1969 automobiles would not be precluded by the Federal Standard, the various States may interpose restrictions as to this lamp. With respect to the requirements of Standard No. 108, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard. |
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ID: aiam0501OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P. O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P. O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Your inquiry concerning the certification required of seat belt installed in motor vehicles manufactured after January 1, 1972, has been brought to our attention. Motor Vehicle Safety Standard No. 208, which governs the installation of seat belts, requires belts to conform to Standard No. 209. Since Standard No. 209 is amended effective January 1, 1972, your question is whether a vehicle manufactured after that date must have seat belts that are certified as conforming to the new provisions of Standard No. 209.; We construe Standard No. 208 to require only that the belts conform t Standard No. 209 as it was at the time of their manufacture. Thus, a belt manufactured before January 1 that conforms to the contemporaneous (pre-amendment) version of Standard No. 209 may be installed in a vehicle manufactured after that date. A belt manufactured after January 1, must, of course, conform to the amended version of the standard.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0503OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P.O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P.O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Your inquiry concerning the certification required of seat belt installed in motor vehicles manufactured after January 1, 1972, has been brought to our attention. Motor Vehicle Safety Standard No. 208, which governs the installation of seat belts, requires belts to conform to Standard No. 209. Since Standard No. 209 is amended affective January 1, 1972, your question is whether a vehicle manufactured after that date must have seat belts that are certified as conforming to the new provisions of Standard No. 209.; We construe Standard No. 208 to require only that the belts conform t Standard No. 209 as it was at the time of their manufacture. Thus a belt manufactured before January 1 that conforms to the contemporaneous (pre- amendment) version of Standard No. 209 may be installed in a vehicle manufactured after that date. A belt manufactured after January 1, must, of course, conform to the amended version of the standard.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: nht92-1.20OpenDATE: 12/16/92 FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA TO: ROBERT R. MCAUSLAND, P.E. ATTACHMT: ATTACHED TO LETTER DATED 10-9-92 FROM ROBERT R. MCAUSLAND (OCC 7854) TEXT: This responds to your letter asking whether your design of an infant seat would comply with S5.2.4 of Federal Motor Vehicle Safety Standard No. 213, Child Restraint Systems. You state that your infant seat would have a frame made from 1/4 inch thick polyethylene sheet, and that all the edges of the frame are rounded to a radius of 1/8 inch. As discussed below, the design would not comply if the edges of the seat frame are contactable by the infant dummy's head or torso during the standard's dynamic test. Some background information on Federal motor vehicle safety laws and regulations may be helpful. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. @ 1381 et seq., Safety Act) authorizes this agency to issue safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA, however, 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. The following represents our opinion based on the facts set forth in your letter. Standard No. 213 specifies requirements for child restraint systems used in motor vehicles and aircraft, to reduce the number of children killed or injured in motor vehicle crashes and in aircraft. S5.2.4, "Protrusion limitation," of Standard No. 213 states: Any portion of a rigid structural component within or underlying a contactable surface, or any portion of a child restraint system surface that is subject to the requirements of S5.2.3 [the head impact protection requirements for infant seats], shall, with any padding or other flexible overlay material removed, have a height above any immediately adjacent restraint system surface of not more than 3/8 inch and no exposed edge with a radius of less than 1/4 inch. (Emphasis added.) The term "contactable surface" is defined in S4 of the standard as "any child restraint system surface (other than that of a belt, belt buckle, or belt adjustment hardware) that may contact any part of the head or torso of the appropriate test dummy, specified in S7, when a child restraint system is tested in accordance with S6.1." Under S5.2.4, any edges of a rigid structural component within or underlying a surface that can be contacted by the head or torso of the appropriate test dummy during Standard No. 213's dynamic test must have a radius of at least 1/4 inch. Since the frame edges of your infant seat have a radius of only 1/8 inch, the seat would not comply with S5.2.4 if the surfaces overlying those edges can be contacted by the infant dummy during the dynamic test. You ask whether, since side loading is not specified in Standard No. 213, can you conclude that there is no way that the child's head or torso could contact the sides of the frame, i.e., that the surfaces overlying those edges cannot be contacted by the infant dummy during the dynamic test. We assume that you believe the infant's head and torso are unlikely to contact the frame's edges in the 213 dynamic test since, due to the forward motion of the test, the dummy's components are likely to move forward and rearward, rather than laterally. I note that, for purposes of compliance testing, NHTSA would determine whether the surfaces are contactable surfaces for the purposes of S5.2.4 by observing a dynamic test, conducted according to the procedures in Standard No. 213. With respect to the issue of what information or analysis would be sufficient, for purposes of certification, for you to conclude that the surfaces overlying those edges cannot be contacted by the infant dummy during the dynamic test, manufacturers must have some basis for their certification that a product complies with all applicable safety standards. However, this does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations. You should be aware, however, that the direction of dummy movement during the Standard No. 213 dynamic test depends on many variables other than the direction of the test, such as the performance of the restraint's belt system. For example, in the event a child seat's upper torso restraint slipped off the dummy's shoulder in the dynamic test, the dummy could move laterally and strike the sides of the restraint system. You should consider all of the variables that could affect the dummy's performance when determining whether frame contact can occur. I also note that manufacturers of motor vehicles and motor vehicle equipment are subject to the defect provisions of the National Traffic and Motor Vehicle Safety Act. Infant restraints are involved in real-world crashes other than the frontal impacts simulated in Standard No. 213. If data indicated that a child seat exposed occupants to an unreasonable risk of injury, such as sharp edges resulting in injuries in a side crash, the agency might conduct a defect investigation which could lead to a safety recall. Enclosed is an information sheet which provides additional information for new manufacturers of motor vehicles and motor vehicle equipment. If you have further questions, please call Ms. Deirdre Fujita of my staff at (202) 366-2992. |
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ID: nht88-4.36OpenTYPE: INTERPRETATION-NHTSA DATE: 12/09/88 FROM: KEITH A. MCDOWELL -- VICE PRESIDENT -- ENGINEERING TRANSPORTATION PRODUCTS GROUP AMERICAN SEATING CO TO: OFFICE OF THE CHIEF COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 03/22/89 FROM ERIKA Z. JONES -- NHTSA TO KEITH A. MCDOWELL, REDBOOK A33, STANDARD 208, STANDARD 209, STANDARD 210; LETTER DATED 02/25/89 FROM KEITH A. MCDOWELL TO NHTSA TEXT: Honorable Chief Counsel: My name is Keith McDowell and I am employed by the American Seating Company as Vice President of Engineering. For your information American Seating is the leading manufacturer of large transit bus seating on the North American Continent. We have long b een an advocate of passenger safety, and our continued concern for safety is evidenced by this letter. Recently, we have received a number of inquires from bus builders regarding the provision of seat belts on our seats. (It is our belief that this trend is the result of concern generated in the school bus market.) Upon reviewing the current Federal Moto r Vehicle Safety Standards, we find that no seat belt standards apply to passenger seating on large buses over 10,000 pounds GVW. We are currently at a loss as to how to respond in a responsible manner to our customers. Inquiries from bus builders are generated when a Transit Authority specifies a requirement for seat belts on transit bus bid documents. These procurements are typically 80% funded by the Urban Mass Transit Administration (no doubt, a familiar agency). Unfortunately, no bid specifications outline the standards to use for design and testing of seat belt installations. Because of the continuing demand from our customers, we are requesting you to provide us guidelines for the design and installation of seat belt assemblies on large buses (over 10,000 pounds GVW). Specifically, these guidelines must address transverse s eat installations (forwarded facing and rearward facing) and longitudinal seat installations (aisle facing). As you well understand, our need is of the utmost urgency as current bids are involved. It is our opinion that federally funded bus procurements specifying seat belts must include guidelines for belt installation and testing so that all suppliers may bi d competitively, fairly, and above all else, with utmost regard for the safety of the public. We look forward to your timely response. Sincerely, |
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ID: aiam4943OpenMr. Terry Semprini Executive Director Cycle Country Accessories Corp. Rt. 3, Box 125 Hwy 71 North Milford, Iowa 51351; Mr. Terry Semprini Executive Director Cycle Country Accessories Corp. Rt. 3 Box 125 Hwy 71 North Milford Iowa 51351; Dear Mr. Semprini: This responds to your letter of December 10, 1991 to Taylor Vinson of this Office, asking whether a lighting device developed by your company 'is legal to run in all of the United States.' From the pictures you enclosed, we note that your device is a diamond-shape lamp, incorporating six amber lamps which form right and left turn signals. In addition, four red lamps are used for stop and hazard warning lamp purposes. These lamps are arranged in a V shape at the top of the device, and an inverted V at the bottom. In the photos you enclosed, the device appears installed near the top of the truck, to the left of the vertical centerline, midway between the centerline and the left edge of the vehicle. It appears that the intent of this device is, in the position depicted, to serve as the vehicle's turn signal lamps, hazard warning signal lamps, and stop lamps in the event that the original equipment lamps were obscured by one or more intervening vehicles. This would occur were the stop lamps and turn signal lamps mounted at the bottom of the vehicle body, as depicted in your photographs. By way of background information, Section 103 of the National Traffic and Motor Vehicle Safety Act (Safety Act, 15 U.S.C. 1392) authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal motor vehicle safety standards for new motor vehicles and new items of motor vehicle equipment. We have exercised this authority to establish Standard No. 108, Lamps, Reflective Devices, and Associated Equipment (49 CFR ?571.108). Standard No. 108 applies to new motor vehicles and to lamps, reflective devices, and associated equipment for replacement of original equipment lamps, reflective devices, and associated equipment. As noted above, it appears that your company's lighting device would be offered as an aftermarket item to supplement, not replace, the original equipment lamps. Assuming this is the case, Standard No. 108 would not directly apply to your company's lighting device and your company would not be required to certify that the lighting device conforms with Standard No. 108. Even though Standard No. 108 does not appear to directly apply to this lighting device, there is a provision of the Safety Act that applies to the installation of aftermarket items of motor vehicle equipment. Section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)) prohibits any manufacturer, distributor, dealer, or repair shop from knowingly 'rendering inoperative,' in whole or in part, any device or element of design installed on or in a vehicle in compliance with an applicable safety standard. The effect of this provision is to make it unlawful for any of the named commercial establishments to add or replace any lamp, reflective device, or associated equipment on a motor vehicle if the commercial establishment knows or should know that the addition of the aftermarket lighting equipment results in the vehicle no longer complying with Standard No. 108. It appears that your company's lighting device would 'render inoperative' the required lighting equipment on a trailer by impairing its effectiveness. First, we note that the device as positioned fails to fulfill basic locational requirements of Standard No. 108 that rear lamps be installed one on each side of the vertical centerline and as far apart as practicable. The signal sent by these lamps could therefore be perceived as conflicting or unclear when viewed simultaneously with the original equipment lamps. Second, we note that the hazard warning system of the device operates through the stop lamps rather than through the turn signal system as is the case with original equipment. This means that a viewer could be faced with the necessity of interpreting the meaning of simultaneously flashing red and amber lamps on the rear of the vehicle, as well as the meaning of the original stop lamps should the brakes also be applied. Finally, we note that the stop lamp portion of the device, two lamps forming a V and two more an inverted V, form a lighting array that the public does not associate as a traditional stop lamp system, usually circular or rectangular lamps. Thus, a viewer to the rear could be faced with a momentary delay in interpreting the meaning of the simultaneous appearance of light from the stop lamps, and from the auxiliary device mounted to the left of center on the rear of the vehicle. For the above reasons, we view your device as having the potential to render inoperative certain rear lamps required on trailers by Standard No. 108. Accordingly, it would be a violation of Federal law for any manufacturer, distributor, dealer, or repair shop to install your company's lighting device on a customer's trailer. This 'render inoperative' prohibition does not apply to individual vehicle owners. Vehicle owners may add lighting devices or make other modifications to their own vehicles without violating any provision of Federal law, even if the owner's modifications result in the vehicle no longer complying with Standard No. 108. However, the individual States are free to establish whatever restrictions, if any, they deem appropriate on individual owner modifications. Thus, a State or States might choose to prohibit individual owners from equipping their trailers with your company's lighting device. We are unable to advise you on the laws of the individual States. You can obtain further information on State laws by writing to: American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, Paul Jackson Rice Chief Counsel; |
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.