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: aiam2632OpenMr. William F. Cox, President, Cox Trailers, Inc., Grifton, NC 28530; Mr. William F. Cox President Cox Trailers Inc. Grifton NC 28530; Dear Mr. Cox: This is in reply to your letter of July 7, 1977, informing us of you wish to relocate combination stop, tail, turn signal and side marker lamps 'to the upper rear fender' of the boat trailers that you manufacture. You have asked whether this location complies with the requirements of Standard No. 108.; I am sorry that we cannot give you the interpretation you seek Standard No. 108 requires that rear side marker lamps be mounted 'as far to the rear as practicable,' and stop, tail, and turn signal lamps must be mounted 'on the rear.' Even though, in your opinion, at your planned fender location 'the lights will pass all of the required photometric and visibility requirements', when the trailer is carrying a boat the lamps are more likely to be visible 'on the rear.' (sic) as the standard requires.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3920OpenMr. Troy C. Martin, Specifications Chief, State Purchasing and General Services Commission, P.O. Box 13047, Capitol Station, Lyndon Baines Johnson State Office Building, Austin, TX 78711- 3047; Mr. Troy C. Martin Specifications Chief State Purchasing and General Services Commission P.O. Box 13047 Capitol Station Lyndon Baines Johnson State Office Building Austin TX 78711- 3047; Dear Mr. Martin: This responds to your January 24, 1985 letter to the National Highwa Traffic Safety Administration (NHTSA) asking about our school bus safety standards.; Your first question asked whether a bus manufactured to accommodate passengers and 3 wheelchair positions to be used for carrying students would be classified as a school bus. The answer to your question is yes. Whether a vehicle is a school bus depends on the seating capacity of the vehicle. NHTSA determines the seating capacity of a motor vehicle by identifying the number of designated seating positions, as defined in 49 CFR Part 571.3, in the vehicle. 'Designated seating position' is defined as:; >>>any plan view location capable of accommodating a person at least a large as a 5th percentile adult female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jumpseats....<<<; Consistent with this definition, we have also counted position designed to accommodate wheelchairs in determining vehicle seating capacity for the determination of vehicle classification. Since your vehicle carries 10 passengers plus a driver, for a total of 11 persons, it is a school bus under Part 571.3 of our regulations.; The second part of this question asked whether this vehicle would b required to comply with the seating requirements of FMVSS No. 222. The answer is yes. Each new school bus must comply with all applicable requirements of Standard No. 222. Some different requirements apply to school buses having gross vehicle weight ratings (GVWR) of 10,000 pounds or less, than to school buses with GVWR's greater than 10,000 pounds. For example, the seat spacing requirements of Standard No. 222 do not apply to the lighter school buses, since these vehicles are required to have safety belts.; Your second question asked whether a vehicle manufactured to carry student passengers would be classified as a school bus. The answer is no. Such a vehicle does not have the passenger capacity of a bus, and is thus not a school bus. Although the school bus safety standards would not apply to this vehicle, it would have to meet the standards set for a multipurpose passenger vehicle.; Your third and fourth questions concerned side facing seats fo handicapped passengers. You first asked whether seat barriers must be placed forward and rearward of a side facing seat, when the seat is positioned between rows of forward facing seats.; I assume that you are concerned with buses having GVWR's greater tha 10,000 pounds, since the seat spacing requirements of S5.2 of Standard No. 222 apply only to these heavier school buses. In a preamble to a July 12, 1976, Federal Register notice (41 FR 28506), the agency determined that the seat spacing requirements of S5.2 are not appropriate for side facing seats designed to accommodate handicapped or convalescent passengers. Therefore, a restraining barrier is not required forward of a side facing seat. However, a restraining barrier must be provided rearward of any side facing seat that has a forward facing seat next to it, in order to compartmentalize the passengers in the forward facing seat.; Your fourth question assumed that S5.2 applied to side facing seats You asked whether the back of a forward facing seat positioned in front of a side facing seat could be used to meet the barrier requirements of S5.2. As discussed above, S5.2 does not apply to side facing seats.; Your fifth question asked whether safety belts are required for sid facing seats on school buses with GVWR's of 10,000 pounds or less, and on school buses with GVWR's greater than 10,000 pounds. For school buses with GVWR's of 10,000 pounds or less, Standard No. 222 requires that the applicable specifications of Standard Nos. 208, 209, and 210, be met 'at all seating positions other than the driver's seat.' Thus each seating position in a small school bus must have a safety belt and anchorages that comply with the applicable requirements of those standards. Side facing seats on the heavier school buses are not required to have safety belts.; Your sixth question asked if we have information on the use of shoulde straps and harnesses with lap belts for passenger seats on school buses. NHTSA has not conducted any tests on the use of shoulder straps or harnesses with safety belts on school buses. You might want to contact school bus manufacturers to discuss how 3-point belt systems can be used in school buses.; Your last question asked whether NHTSA has any plans at the present t delete the safety belt requirements for school buses with GVWR's of 10,000 pounds or less. Although NHTSA has no present plans to delete the safety belt requirement for the lighter school buses, the agency is presently reviewing the Canadian test data to which you referred in your letter. If we believe there is a need to propose to amend Standard No. 222, the public will have an opportunity to submit comments.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam3473OpenMr. John H. Shafer, Director, Traffic and Safety Division, Department of Transportation, 1220 Washington Avenue, State Campus, Albany, NY 12232; Mr. John H. Shafer Director Traffic and Safety Division Department of Transportation 1220 Washington Avenue State Campus Albany NY 12232; Dear Mr. Shafer: This responds to your September 8, 1981 letter enclosing correspondenc from Mrs. Barbara Stephens asking about extending the seat spacing in a school bus that is designed to transport handicapped children. You ask for general guidance in this area.; First, let me say that the safety standards apply to manufacturers o vehicles as well as those individuals that alter new motor vehicles. Further, repair businesses are not permitted to render inoperative the compliance of a vehicle with the safety standards. On the other hand, nothing prohibits an individual from rendering inoperative the compliance of his or her own vehicle with any safety standard.; In specific reference to seat spacing in school buses, two genera rules apply. First, seat spacing is not regulated in vehicles with gross vehicle weight ratings (GVWR) of 10,000 pounds or less. Accordingly, any modification of seat spacing in these vehicles is permissible. Second, in vehicles with GVWR's in excess of 10,000 pounds, seat spacing is regulated, and a manufacturer may not produce a vehicle whose spacing exceeds the specifications set in Standard No. 222, *School Bus Passenger Seating and Crash Protection*. Further, a repair business may not affect the seat spacing in a way that would violate the standard. An owner, however, may change the spacing in her or her own vehicle.; The agency has specifically provided for the transportation of th handicapped by allowing the installation of side-facing seats in school vehicles designated for handicapped transportation. We would suggest that this is a more suitable approach than extending seat spacing. By extending seat spacing, a school would be taking its vehicles out of compliance with the safety standards. In the event of an accident involving one of these vehicles, the school might be subject to unnecessary liability for having made these modifications to its vehicles.; I hope that this will be of use to you in advising schools of th Federal requirements, and if I can be of further assistance, please contact me.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3189OpenMr. Doug Smith, 3595 Santa Fe Avenue #156, Long Beach, California 90810; Mr. Doug Smith 3595 Santa Fe Avenue #156 Long Beach California 90810; Dear Mr. Smith: This responds to your December 6, 1979, letter asking questions abou Standard No. 211, *Wheel Nuts, Wheel Discs, and Hub Caps*. In particular, you ask whether winged projections are permitted in a rim as long as they do not extend beyond the lip of a rim or the sidewall of a tire.; When the standard was issued, the agency concluded that winge projections could catch the clothing of children or pedestrians thereby posing safety hazard. As a result the standard prohibits the use of all winged projections regardless of the extent to which they extend from a rim. The standard however, only prohibits winged projections and does not affect other projects from a rim.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3023OpenMr. Raymond L. Smallwood, Retread Plant Manager, Montgomery Tire Service, Inc., Box 515, Gaithersburg, Maryland 20760; Mr. Raymond L. Smallwood Retread Plant Manager Montgomery Tire Service Inc. Box 515 Gaithersburg Maryland 20760; Dear Mr. Smallwood: This is in reply to your letter of April 26, 1979, with respect to you wish to import used truck tire casings for the purposes of recapping. You have been advised in a telephone conversation with our Office of Vehicle Safety Compliance that there are two ways to do this: the casings must bear DOT markings, or be accompanied by some proof that they were manufactured before March 1, 1975, the effective date of the truck tire standard, Federal Motor Vehicle Safety Standard No. 119. So believe that this is impossible and have requested our advice.; There is an additional solution whose feasibility we will leave to you determination. While Section 108(a)(1)(A)(15 U.S.C. 1397(a)(1)(A)) of the National Traffic and Motor Vehicle Safety Act, as we interpret it, prohibits the importation of used truck tires that do not comply with Standard No. 119, Section 108(b)(3) (15 U.S.C. 1397 (b)(3)) allows their importation under bond 'to insure that any such [tire] will be brought into conformity with any applicable Federal motor vehicle safety standard' (The corresponding provision of the importation regulation is 19 CFR 12.80(b)(i)(3)). Since the agency presently has no standard that applies to the retreading of truck tires, the applicable standard would be that in effect when the tires was new - Standard No. 119. Thus, if Montgomery Tires Service can demonstrate that its retreaded truck tires conform to Standard No. 119, and are willing to affix a DOT symbol to each tire as certification of that fact, your casings may enter the country under bond as provided for in 19 CFR 12.80 (b) (i) (3), releasable when upon an affirmation of compliance to Standard No. 119.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4709OpenMr. Kent D. Smith 12249 S. 1565 E. Draper, UT 84020; Mr. Kent D. Smith 12249 S. 1565 E. Draper UT 84020; Dear Mr. Smith: This is in reply to your letter of January 26, l990, t the agency with respect to a safety lighting device. You have asked for our recommendations regarding this invention. The problem addressed by your invention is 'that vehicles need some way of signaling following drivers if the headlamps of their vehicles are blinding you.' Your solution is to install a button that activates the backup lamps and extinguishes them in a matter of a second or less. One alternative would be to operate only a single backup lamp, and another, to activate only the license plate lamp. This would provide a warning to the following driver. The agency is concerned with glare, but its investigation of the phenomenon indicates that there are two types: discomfort glare, and disabling glare. Although it is certainly an annoyance, the glare produced by a headlamp shining into a rear view mirror is discomfort glare. In our judgment, a vehicle driver looking into the mirror will not suffer disabling glare so that he is unable to discern vehicles approaching, or pedestrians in the roadway, most vehicles are equipped with manual 'day/night' mirrors which may be easily operated in the event of discomfort. Equipment manufacturers have already addressed the problem by providing rear-view mirrors that have a photoelectric cell that dips them when a certain level of light intensity is reached. In summary, the agency does not believe that there is a nationwide safety problem requiring it to mandate the use of your device on motor vehicles as new vehicle equipment. As an aftermarket item which a dealer could offer a new-car purchaser, its installation would be subject to the general prohibition in Federal Motor Vehicle Safety Standard No. 108 that supplemental lighting devices shall not impair the effectiveness of the lighting equipment that Standard No. 108 requires. The question to be answered, therefore, is whether the device would impair the effectiveness of the backup lamps, or other rear lighting devices. The problem here is the necessity of rear lighting devices to provide clear and unambiguous signals and messages to following drivers. Anytime a lighting device does not provide a cue to which a following driver is accustomed, the potential for confusion arises. The driving public is unfamiliar with the sudden, though temporary, activation of the backup lamp, at normal driving speeds, or a modification in intensity of the license plate lamp. Without a substantial nationwide public education campaign, the signal imparted by your device is not likely to be understood by a following driver, and might distract him from the signals of the other rear lighting devices. In this sense, we believe that your device might impair the effectiveness of the lighting equipment that Standard No. 108 does allow. You have also noted the State prohibitions against use of backup lamps when the car is going in a forward direction. Even if the agency concluded that the device was permissible and would not cause impairment, the States are not precluded from enacting and enforcing their own standards on the use of lighting systems. You may be interested to know that two letters to the Editor of The New York Times have appeared on this issue in the last month which suggest the use of existing lighting equipment to signal following drivers that their upper beams are on. I enclose these letters for your consideration. I am sorry that we cannot be more encouraging in our remarks, but we do appreciate your interest in motor vehicle safety. Sincerely yours, Stephen P. Wood Acting Chief Counsel Enclosure; |
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ID: aiam3536OpenMr. E. L. Anderson, Project Engineer, Transportation Products Inc., P.O. Box 329, Suffern, NY 10901; Mr. E. L. Anderson Project Engineer Transportation Products Inc. P.O. Box 329 Suffern NY 10901; Dear Mr. Anderson: This responds to your February 18, 1982, letter asking for a interpretation of Standard No. 217, *Bus Window Retention and Release*. In particular, you question the requirement of section S5.3.3 which specifies that a continuous warning device shall sound when a school bus ignition is in the 'on' position and the release mechanism for an emergency door is not closed. You ask whether depressing the button on the outside of the door should activate the warning device.; The actual requirement of S5.3.3 states that the warning device must b audible when the *release mechanism* is not in the closed position. The release mechanism is that mechanism that keeps the door from opening. So, for example, if the outside button were depressed but the actual door latch did not open and the door would not itself open, it would not be necessary for the warning device to actuate. However, I assume that the outside button releases the latch which in turn allows the door to open. If this is the case, then at the moment that the latch is released, the warning device must be audible. If this did not occur, it would be possible that the door could be in an open position with the vehicle operating and without the knowledge of the occupants.; I hope that this resolves the question for you. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4359OpenMr. M. Iwase, Manager, Technical Administration Dept. Koito Mfg., Ltd., Shizuoka Works, 500, Kitawaki, Shimizu-Shi, Shizuoka- ken, Japan; Mr. M. Iwase Manager Technical Administration Dept. Koito Mfg. Ltd. Shizuoka Works 500 Kitawaki Shimizu-Shi Shizuoka- ken Japan; Dear Mr. Iwase: This is in reply to your letter of March 24, 1987, asking two question with respect to Motor Vehicle Safety Standard No.108; Your first question concerns an aiming adaptor for replaceable bul headlamps whose lenses may slant 60 degrees from the vertical or horizontal. You have discovered that the Hopkins universal adaptor cannot be used with these headlamps, and you propose to provide a special adaptor with each vehicle equipped with such headlamps, as well as aiming adjustment procedure information in the vehicle's service manual. You ask for confirmation of your belief that this is permissible under Standard No. 108.; Standard No. 108 does not require that an aiming adaptor be provide with a motor vehicle, only that its headlamps be capable of mechanical aim. Therefore there is no legal requirement that the adaptor be provided. However, without such an adaptor, an owner of a vehicle with the 60-degree headlamps may encounter difficulties of State inspection stations where mechanical aimers are in use, and at repair facilities when headlamps are replaced or after body work has been performed that necessitates reaim of headlamps. Therefore we believe that provision of the adaptor and aiming information would enhance consumer acceptance of the 60- degree headlamps.; Your second question concerns the legality of the upper aiming boss o a low profile headlamp. Because the height of the lens is insufficient to incorporate the upper aiming boss, you propose to place it on a flange of the lens in a 'photometrically ineffective area.' However, the flange is concealed when the hood is shut, and the hood must be opened in order for aiming adjustment to occur. You believe that this is acceptable under Standard No. 108. and ask for confirmation.; Paragraph S4.1.1.36 (a)(2) requires that 'the lens of each replaceabl bulb headlamp shall have three pads which meet the requirements of Figure 4....' Your drawing indicates that the flange is part of the headlamp lens even though that portion of the lens is not needed to provide illumination. Therefore this design would appear to meet the requirements of Figure 4 as you have concluded.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3166OpenMr. Bruce Henderson, Automobile Importers of America, Inc., 1735 Jefferson Davis Highway, Suite 1002, Arlington, Virginia 22202; Mr. Bruce Henderson Automobile Importers of America Inc. 1735 Jefferson Davis Highway Suite 1002 Arlington Virginia 22202; Dear Mr. Henderson: #This is in response to your October 29, 1979 request for an interpretation of the Federal motor vehicle safety standards. You asked whether vehicles equipped with space-saver spare tires must be tested for compliance with Federal motor vehicle safety standards with that spare tire actually used as one of the four tires mounted on the vehicle during the tests. Our interpretation is that the spare tire need not be used during those tests. #This agency does not currently require that a motor vehicle be equipped with a spare tire. If a spare tire is included with the vehicle, it must, of course, comply with all standards applicable to tires. #Sincerely, Frank Berndt, Chief Counsel; |
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ID: aiam5118OpenMs. Joanna L. Campfield Vice President Ultra B-O-N-D, Inc. 11151 Pierce Street Riverside, CA 92505; Ms. Joanna L. Campfield Vice President Ultra B-O-N-D Inc. 11151 Pierce Street Riverside CA 92505; "Dear Ms. Campfield: This responds to your letter asking the Nationa Highway Traffic Safety Administration (NHTSA) to issue an 'approval' letter for your method of repairing cracks in windshields. As explained below, this agency does not approve motor vehicles or items of motor vehicle equipment. However, this letter does discuss Federal safety requirements in connection with windshield repairs. By way of background information, section 103 of the National Traffic and Motor Vehicle Safety Act of 1966 (Safety Act, 15 U.S.C. 1392) authorizes this agency to issue safety standards applicable to new motor vehicles and items of new motor vehicle equipment. NHTSA, however, does not approve motor vehicle 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 our safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates alleged safety-related defects. NHTSA has issued Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205) which establishes performance and location requirements for glazing used in new motor vehicles and for all new replacement glazing for motor vehicles. Neither Standard No. 205 nor any other FMVSS establishes performance requirements for repair kits, such as the Ultra B-O-N-D method, used to repair cracks in broken glazing. However, use of such a material or process in a new windshield prior to the first consumer purchase which requires repair, for example, as a result of damage sustained in shipment would be affected by Standard No. 205. Manufacturers must certify that their new vehicles comply with all applicable safety standards. If a windshield is repaired prior to the new vehicle being sold for the first time to a consumer, the person making the repairs would be considered a vehicle alterer under our certification regulations (Part 567). As an alterer, the person would have to certify that the vehicle, as altered, continues to comply with all of the requirements of Standard No. 205. In the case of a used vehicle, use of a windshield repair kit could potentially be affected by section 108(a)(2)(A) of the Safety Act. That section prohibits commercial businesses from knowingly rendering inoperative devices or elements of design installed in a vehicle in compliance with a FMVSS. In discussing the applicability of section 108(a)(2)(A) to the repair of windows in used vehicles, NHTSA has said that the prohibitions of that section do not apply to use of a product or process used in the repair of a windshield which has been previously installed in a vehicle and damaged in use. The agency has considered the event that damaged the windshield, and not any subsequent action by the person repairing the damaged window in a used vehicle, as the event which rendered inoperative the compliance of the glazing with the standard. Thus, there is no Federal regulation which would prohibit the use of a product or process in the repair of a windshield which has previously been installed in a vehicle and damaged in use. I note, however, that if the repair shop, in the course of fixing a damaged windshield that is installed in a vehicle renders another part of the vehicle or element of design inoperative with respect to another applicable Federal motor vehicle safety standard, then the repair shop would violate section 108(a)(2)(A). In addition, the manufacturer of the windshield repair kit is considered a manufacturer of motor vehicle equipment. Accordingly, it is subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. Please be aware that the laws of the individual States may be relevant to the repair of motor vehicle glazing. For more information about these laws, you should contact the American Association of Motor Vehicle Administrators. Its address is 4600 Wilson Boulevard, Arlington, Va. 22203. I hope this information is helpful. Please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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.