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: aiam3708OpenMr. William E. Meiter, Middletown Van Pool Association, 60 Wallace Road, Middletown, NJ 00748; Mr. William E. Meiter Middletown Van Pool Association 60 Wallace Road Middletown NJ 00748; Dear Mr. Meiter: This responds to your note of May 27, 1983, attaching correspondenc between yourself and a District Manager for Ford Motor Company. You requested that we investigate the Ford E-150 van (which you state is a 15-passenger van) to determine if the stated Gross Vehicle Weight Rating of that vehicle is accurate.; Each manufacturer of a motor vehicle is required by the agency' regulations to place a certification label on the vehicle specifying that the vehicle is in compliance with all Federal motor vehicle safety standards and regulations (issued pursuant to the National Traffic and Motor Vehicle Safety Act of 1966). This certification label must include information regarding the vehicle's Gross Vehicle Weight Rating, as specified in 49 CFR 567.4(g)(3):; >>>(3) 'Gross Vehicle Weight Rating' or 'GVWR', followed by th appropriate value in pounds, which shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity. However, for school buses the minimum occupant weight allowance shall be 120 pounds.'<<<; Thus, you are correct in your assumption that the GVWR for 15-passenger vehicle would have to include 2,250 pounds for occupant weight. Further, if a 15- passenger vehicle has a stated GVWR of 6,200 pounds, its unloaded vehicle weight could not exceed 3,950 pounds. I cannot state whether the Ford E-150 van has an unloaded vehicle weight in excess of this figure. However, I am sending a copy of your correspondence to our Office of Enforcement so that they may review this matter.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3909OpenMr. Fred W. Bowditch, Vice President, Technical Affairs Division, Motor Vehicle Manufacturers Association, 300 New Center Building, Detroit, MI 48202; Mr. Fred W. Bowditch Vice President Technical Affairs Division Motor Vehicle Manufacturers Association 300 New Center Building Detroit MI 48202; Dear Mr. Bowditch: On October 29, 1984, the Motor Vehicle Manufacturers Association file a petition for rulemaking to amend Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*. The petition requested 'removal from section 4.1.1.36(a)(2) of the limitation requiring the three aiming pads to be located on the exterior face of the headlamp lens.' You have suggested the mounting flange at the lens-reflector joint as an acceptable alternative location for the aiming pads. The language suggested in the petition for amendment of S4.1.1.36(a)(2) would also allow all three legs to be adjustable on the headlamp aimers.; The agency has proposed amendments to Standard No. 108 (49 FR 47880) t delete the final sentence of paragraph S4.1.1.36(a)(2) with reference to aiming locating plates, and to delete Figures 9-1 and 9-2. Thus, this aspect of your petition has already been granted. We have filed your petition as a comment in the docket to be considered in future rulemaking action on this subject. Further, we interpret the words 'The exterior face of each...lens' in paragraph S4.1.1.36(a)(2) to mean all portions of the lens face including the mounting flange which is a molded and indivisible part of the lens. Thus, no rulemaking is considered necessary to implement this item of your petition. Your request also included a suggestion that the minimum height of the lettering for the adjustment of the legs on the aimer adapter should be reduced from 0.25 inch to 4 mm. This is being addressed in pending rulemaking. Therefore, no further action is necessary at this time.; Sincerely, Barry Felrice, Associate Administrator for Rulemaking |
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ID: aiam3876OpenMr. John S. Cucheran, Vice President, Design and Engineering, Jac Products, Inc., 1901 E. Ellsworth, Ann Arbor, MI 48104; Mr. John S. Cucheran Vice President Design and Engineering Jac Products Inc. 1901 E. Ellsworth Ann Arbor MI 48104; Dear Mr. Cucheran: This is in reply to your letter of November 30, 1984, to Mr. Vinson o this office asking for an interpretation of Motor Vehicle Safety Standard No. 108 *Lamps, Reflective Devices, and Associated Equipment*.; Figure 10 of Standard No. 108 establishes the minimum desig photometrics for center high mounted stoplamps. The test procedure for this particular part of Standard No. 108 which is specified in SAE J186a, stipulates that the 'lamp axis shall be taken as the horizontal line through the light source.' However, I believe that you have misinterpreted the light cone that is involved. The pertinent light cone in this case has its vertex at the photometer and a cross section at the plane of the lamp which encompasses the lens areas. From Drawing A that you have provided, it appears that your rail would interfere with this light cone.; In order to determine if your rack interferes with the photometri requirements, the vehicle must be tested with the rack in position as installed on the vehicle. As the agency has noted before, the photometric requirements do not specify that the entire lens must be visible from each 5 degree down test point. Instead, they specify the intensity of light that must be visible from those points. Therefore, the requirement can be met with a lamp whose lens is partially obscured by a portion of the vehicle when viewed from some of the test points.; We hope that his interpretation is helpful to you. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5042OpenMr. R.J. Misorski Director, Maintenance & Repair Maersk Inc. 231 Tyler Street Port Newark, NJ 07114; Mr. R.J. Misorski Director Maintenance & Repair Maersk Inc. 231 Tyler Street Port Newark NJ 07114; "Dear Mr. Misorski: This responds to your letter of August 6, 1992 asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. You write with reference to an amendment that became effective December 1, 1991, requiring a minimum of 12 square inches of lens area for rear stop or turn signals on vehicles over 80 inches wide, regardless of the separation between lamps. You request confirmation of your feeling that 'equipment manufactured prior to December 1, 1991 would be exempt from this ruling', and that 'it only applies to equipment that is manufactured after December 1, 1991.' You have asked for this interpretation to 'ensure compliance with our equipment fleet.' What the amendments require is that multipurpose passenger vehicles, buses, trucks, and trailers whose overall width is 80 inches or more, which are manufactured on and after December 1, 1991, be equipped with stop and turn signal lamps that meet the new requirements. Stop and turn signal lamps which were manufactured prior to that date that do not meet the new requirements are permissible to replace original equipment of the same type on vehicles manufactured before December 1, 1991, but they cannot be used as either original or replacement stop and turn signal lamps on vehicles manufactured on and after December 1, 1991. Furthermore, Standard No. 108 continues to allow manufacture and sale on and after December 1, 1991, of the old type of stop and turn signal lamps for replacement of original equipment on vehicles manufactured prior to December 1, 1991. I hope that this assists you with your compliance question. We shall be pleased to answer any further questions you may have. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam1228OpenMr. C. F. Robb, Manager, Electrical Testing Laboratories, Inc., 2 East End Avenue, New York, NY 10021; Mr. C. F. Robb Manager Electrical Testing Laboratories Inc. 2 East End Avenue New York NY 10021; Dear Mr. Robb: This is in reply to your letter of June 18, 1973, concerning th conformity of certain designs of type III seat belt assemblies with Standard No. 209.; The first feature which you describe is a restraint consisting of waist band with a single shoulder strap. The shoulder strap is attached to the buckle in front and is looped around the waist band in back. Unless this restraint has more elements than you describe, we have serious questions about its conformity with the requirements for type III seat belts under Standard 209. Section S4.1(c) provides that the assembly must restrain the upper torso without shifting the pelvic restraint into the abdominal region and that the upper torso restraint shall be designed to minimize its vertical forces on the shoulders and spine. It appears doubtful that the described assembly meets either of these requirements.; The second feature you describe is a strap through the harness assembl that passes around the seat back and is anchored to the floor by means of the vehicle's seat belt assembly anchorage. Your question appears to be whether such a restraint is a seat back retainer as required by Section S4.1(h). The attachment you describe would not be a seat back retainer under Section S4.1(h).; The third feature described, a closed loop strap without floo attachment would also violate the requirements of S4.1(h), unless it is designed and labeled for use only in specific models having adequate seat back restraints, as specified in that paragraph.; The fourth feature is the ability of a harness to move freely up an down on the restraint strap. This feature is allowable under Standard 209.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0404OpenMr. J. Wuddel, Westfalische Metall Industrie KG, Rusck and Company, 4760 Lippstadt, Postfach 604, Republic of West Germany; Mr. J. Wuddel Westfalische Metall Industrie KG Rusck and Company 4760 Lippstadt Postfach 604 Republic of West Germany; Dear Mr. Wuddel: This is in reply to your letter of July 7, 1971, to the Nationa Highway Safety Bureau (now the National Highway Traffic Safety Administration) concerning the requirements for sealed beam headlamp units.; The answers to your specific questions are as follows: >>>1. Sealed beam units must meet the photometric specifications in SA J579 at the design voltage at or below the maximum amperes specified in SAE J573.; 2. Tolerances are as follows: *Electrical power* - the maximum electrical power is the product, i watts, of the design voltage multiplied by the maximum amperes at design volts. There is no specified minimum electrical power.; *Maximum amperes* - There is no tolerance. Maximum amperes is th maximum specified in SAE J573.; *Design watts* - There is no tolerance. There is, however, a toleranc on the actual watts or electrical power as described above.; 3. & 4. The filament types and positions are illustrative of curren practice only. Any type or position may be used to meet the specifications of J579 and J573.; 5. All glass sealed beam units are not mandatory. There are n restrictions in Federal Motor Vehicle Safety Standard No. 108 or the SAE Standards on the number of pieces or the materials which are used to complete the assembled sealed beam unit as long as the specifications, including those in SAE J571, are met. Caution should be used, however, to ensure that a good and durable seal is obtained between the metal back, if used, and the other parts to optimize the useful service life of the sealed beam unit.<<<; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam3896OpenMr. H. Moriyoshi, Executive Vice President and General Manager, Mazda (North America), Inc., 24402 Sinacola Court, Farmington Hills, MI 48016; Mr. H. Moriyoshi Executive Vice President and General Manager Mazda (North America) Inc. 24402 Sinacola Court Farmington Hills MI 48016; Dear Mr. Moriyoshi: This is in reply to your letter of November 21, 1984, asking for a interpretation of Motor Vehicle Safety Standard No. 108 as it would apply to a contemplated parking lamp system.; Usually passenger cars are designed with two parking lamps, one on eac side of the vehicle front. Mazda would have two such lamps on each vehicle side, each of the two lamps flanking the headlamp. You have asked whether, in determining the H-V axis, one takes the axis as the center of each lamp, or should one consider the pair a single device and place the H-V axis at the midpoint between them.; Standard No. 108 requires passenger cars to be equipped with a minimu of two parking lamps, located 'as far apart as practicable.' Therefore, the outermost parking lamp, (the one located between the turn signal lamp and the headlamp is the lamp that must meet the parking lamp requirements of Standard No. 108, and the H-V axis for purposes of compliance would be determined at the center of the lens of that lamp. Supplementary lighting equipment is permissible under Standard No. 108 and does not have to meet the Standard's requirements, but it must not impair the effectiveness of the lighting equipment required by the standard (paragraph S4.1.3). Because of the difference in candela between parking lamps and headlamps, information available to us does not indicate that your supplementary parking lamp would have this effect, and consequently, the design would be permitted.; I hope that this answers your questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1716OpenMr. C. Henderson, Director of Engineering, American Safety Equipment Corp., 500 Library Street, San Fernando, CA 91340; Mr. C. Henderson Director of Engineering American Safety Equipment Corp. 500 Library Street San Fernando CA 91340; Dear Mr. Henderson: This is in reply to your letter of October 17,1974, requesting ou opinion on whether a torso pad you wish to utilize in a newly-designed child seating system must conform to the requirements of paragraph S4.10.1 of Standard No. 213, 'Child Seating Systems' (49 CFR S 571.213). The enclosed description, diagrams, and pictures of the pad show that it is attached directly to the harness restraint of the seating system. You suggest that because it works with the restraint webbing, it provides a cushioning function more or less like deformable, force-distributing material. You also suggest that it falls under the exclusion for belt adjustment hardware.; In our view, based on the information you provide, the torso pad is rigid component of the child seating system, and is subject to the requirements for padding and minimum radii of paragraph S4.10.1. The fact that the pad is attached to the belt system does not alter this conclusion. Paragraph S4.10.1 refers to 'any rigid component,' and the torso shield must be evaluated as a component separately from the belt system or any other component. We have determined that rigid should be interpreted in its normal, dictionary sense, and it appears from the information you have provided that the torso pad by itself is rigid in nature.; We can neither agree that because the torso pad acts as a bel adjustment system it falls within the exemption for 'belt adjustment hardware.' That exemption is intended to apply only to traditional belt adjustment hardware mechanisms, which are generally completely integrated into the belt webbing and do not protrude from it.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2614OpenHonorable Clarence D. Long, House of Representatives, Room 200, Post Office Building, Towson, Maryland 21204; Honorable Clarence D. Long House of Representatives Room 200 Post Office Building Towson Maryland 21204; Dear Mr. Long: Your letter of May 9, 1977, to the Federal Trade Commission, on behal of Mr. Edward L. Armstrong, Sr., Baltimore, Maryland, expressing his concern that new passenger car manufacturers will discontinue supplying spare tires, has been referred to this office of the National Highway Traffic Safety Administration, Department of Transportation, for additional consideration and reply.; We believe that Mr. Armstrong's concern deals with the recentl approved 'temporary use' spare tire that will be manufactured and used with some of the new 1978 model automobiles. the use of a temporary use spare tire is not a new concept. These tires have been used with compact sport cars, such as Firebird and Camaro, since 1967. The further development of these spare tires has been fostered by the desire if the U.S. automobile manufacturers to produce small, lightweight cars in furtherance of the national energy conservation program. I am sure that you have noticed the new 1977 models by some domestic automobile manufacturers are, in fact, smaller. Of course, the development of these smaller, lightweight, energy-efficient automobiles has resulted in a substantial reduction in usable car trunk space, and therefore, providing a second reason to develop a spare tire which takes less storage space than a conventional tire.; Since this spare tire is designed for use in the nation's highways, i must conform to the minimum performance requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 109, *New Pneumatic Tires - Passenger Cars*, for strength, endurance and high speed performance, For your information, we have enclosed a copy of this standard.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam3707OpenMr. William E. Meiter, Middletown Van Pool Association, 60 Wallace Road, Middletown, NJ 00748; Mr. William E. Meiter Middletown Van Pool Association 60 Wallace Road Middletown NJ 00748; Dear Mr. Meiter: This responds to your note of May 27, 1983, attaching correspondenc between yourself and a District Manager for Ford Motor Company. You requested that we investigate the Ford E-150 van (which you state is a 15-passenger van) to determine if the stated Gross Vehicle Weight Rating of that vehicle is accurate.; Each manufacturer of a motor vehicle is required by the agency' regulations to place a certification label on the vehicle specifying that the vehicle is in compliance with all Federal motor vehicle safety standards and regulations (issued pursuant to the National Traffic and Motor Vehicle Safety Act of 1966). This certification label must include information regarding the vehicle's Gross Vehicle Weight Rating, as specified in 49 CFR 567.4(g)(3):; >>>(3) 'Gross Vehicle Weight Rating' or 'GVWR', followed by th appropriate value in pounds, which shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity. However, for school buses the minimum occupant weight allowance shall be 120 pounds.'<<<; Thus, you are correct in your assumption that the GVWR for 15-passenger vehicle would have to include 2,250 pounds for occupant weight. Further, if a 15- passenger vehicle has a stated GVWR of 6,200 pounds, its unloaded vehicle weight could not exceed 3,950 pounds. I cannot state whether the Ford E-150 van has an unloaded vehicle weight in excess of this figure. However, I am sending a copy of your correspondence to our Office of Enforcement so that they may review this matter.; Sincerely, Frank Berndt, Chief Counsel |
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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.