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: 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: 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: aiam3762OpenMs. Susan Reilly, Reilly Manufacturing, P.O. Box 51, Mt. Vernon, IA 52314; Ms. Susan Reilly Reilly Manufacturing P.O. Box 51 Mt. Vernon IA 52314; Dear Ms. Reilly: This responds to your letter asking whether a motorcycle helme fastener your company produces, called 'Alpha Clip,' complies with Federal requirements.; By way of background information, this agency does not give approval of vehicles or equipment. The National Traffic and Motor Vehicle Safety Act places the responsibility on the manufacturer to ensure that its vehicles or equipment comply with applicable standards.; Safety Standard No. 218, *Motorcycle Helmets*, includes various minimu performance requirements for motorcycle helmets. The only requirement directly relevant to your fastener is the retention test, which is set forth at section S5.3. The letter you enclosed from the University of Southern California suggests that the clip passes that test.; I would note that Standard No. 218 only applies to new motorcycl helmets and not to replacement equipment for motorcycle helmets. Thus, unless your clip was sold as part of a new motorcycle helmet, the requirements of Standard No. 218 would not be directly applicable. (Please note, however, that the agency discourages helmet users from modifying their helmets. Section S5.6.1 of the standard requires that the following instruction be placed on helmets: 'Make no modifications....'); I would also note that should a safety- related defect be discovered i your device, whether by the agency or by yourself, you as the manufacturer would be required under sections 151 *et seq*. of the Act to notify owners, purchasers, and dealers and provide a remedy for the defect. These provisions apply regardless of whether the device is covered by a safety standard. A copy of the Act is enclosed.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1823OpenMr. Al Zajic, American Trailers, Inc., 1500 Exchange Avenue, Box 26568, Oklahoma City, OK 73126; Mr. Al Zajic American Trailers Inc. 1500 Exchange Avenue Box 26568 Oklahoma City OK 73126; Dear Mr. Zajic: This responds to your February 19, 1975, request for confirmation tha the building of a trailer with some used components constitutes the manufacture of a new vehicle for purposes of meeting all applicable safety standards, unless the running gear and bottom rails, at a minimum, are from an existing trailer. You also ask for confirmation that parking brakes are not required on a steerable front axle of a full trailer.; The answer to both of your questions is yes. I enclose a copy of letter interpretation which sets out our position on the extent to which a vehicle can be 'repaired' before it becomes the manufacture of a new vehicle.; In answer to your second question, a full trailer, like all othe air-braked trailers, must meet the requirements of S5.6 *Parking brake system*. Section S5.6 permits the manufacturer the option of meeting the requirements of S5.6.1, *Static retardation force*, or S5.6.2, *Grade holding*.; If you choose to meet S5.6.1, you are not required to equip the fron steerable axle with a parking brake system. If you choose to meet S5.6.2, you may use whatever combination of parking brake systems will meet the grade-holding requirement, and such a combination may or may not include a parking brake system on the front steerable axle.; Because Standard No. 121 does not specify a secondary means of brakin on the steerable axle, the Bureau of Motor Carrier Safety requirement for automatic application of the brakes upon breakaway remains applicable to the axle (49 CFR S 393.42(d)).; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0842OpenMr. Richard Stevens, Cody Chevrolet, Inc. Barre-Montpelier Road, Montpelier, VT 05602; Mr. Richard Stevens Cody Chevrolet Inc. Barre-Montpelier Road Montpelier VT 05602; Dear Mr. Stevens: This is in reply to your letter of August 1, 1972, to the attention o Mr. Jerome Palisi of our White Plains, New York Office, concerning certification requirements for a vehicle which you describe and indicate will be used by a college to transport ball teams and school personnel, but will not be equipped with flashing lights or other special school bus equipment. You apparently wish to know whether you must consider this vehicle as a school bus for purposes of certification to Federal requirements.; 'School bus' is defined in the motor vehicle safety standards to mean bus 'designed primarily to carry children to and from school, but not including buses operated by common carriers in urban transportation of school children' (49 CFR 571.3). Based upon the description you provide, the NHTSA would not consider the vehicle you describe to be a school bus. For purposes of certification to Federal requirements (49 CFR Parts 567 and 568), there, 'gross vehicle weight rating' should not be computer under the minimum values specified for school buses. In addition, the requirement that vehicle type be inserted on the certification label should be met in inserting, 'BUS.'; This letter should not be construed to mean that the NHTSA takes position as to whether this vehicle need, under State law, conform to requirements for school buses. The State must determine the scope and application of its own laws.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2865OpenMr. Robert B. Kurre, Director of Engineering, Wayne Corporation, P. O. Box 1447, Industries Road, Richmond, IN 47374; Mr. Robert B. Kurre Director of Engineering Wayne Corporation P. O. Box 1447 Industries Road Richmond IN 47374; Dear Mr. Kurre: This responds to your recent letter asking whether Safety Standard No 208 applies to side-facing seats in multi-purpose passenger vehicle vans. You also ask to be advised of the criteria to be used for the installation of seat belts in these vehicles.; Safety Standard No. 208, *Occupant Crash Protection*, does requir side-facing seats in multipurpose passenger vehicles to comply with one of the options under paragraph S4.2.2, since the side-facing seats in question would be considered designated seating positions. If a manufacturer chooses to install seat belts under one of the options of that paragraph, the seat belt assemblies must comply with Safety Standard No. 209, *Seat Belt Assemblies*, and Safety Standard No. 210, *Seat Belt Anchorages*.; Safety Standard No. 210 does exempt side-facing seats from its strengt requirements, but all other requirements of the standard would be applicable. However, we strongly recommend that belt anchorages for side- facing seats be of at least equivalent strength to anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. Side-facing seats were excepted from the strength requirements specified in the standard because the forces acting on side-facing seats are different from those acting on forward or rearward facing seats and the requirements and procedures were specifically developed for these latter seats.; Please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3059OpenMr. Peter Bigwood, Chief Engineer, Ontario Bus Industries Inc., 5395 Maingate Drive, Mississauga, Ontario; Mr. Peter Bigwood Chief Engineer Ontario Bus Industries Inc. 5395 Maingate Drive Mississauga Ontario; Dear Mr. Bigwood: This responds to your July 16, 1979, letter asking two questions abou the test procedures of Standard No. 217, *Bus Window Retention*, as they apply to buses you manufacture.; First, you ask whether side service doors can be counted in determinin the proper amount of bus emergency exits as required by the standard. As long as side service doors comply with all requirements applicable to emergency doors, they can be considered emergency exits for purposes of compliance with the standard.; Your second question asks whether glazing in a door is tested fo window retention, and if so, whether it is tested while the door is installed in a bus. The answer to both parts of this question is yes. All bus glazing, that is of the minimum size specified in the standard, must comply with the window retention requirement. The intent of the window retention requirement is to prevent openings in buses that might result in the ejection of occupants from the vehicle during an accident. In order for this requirement to have meaning, the glazing must be tested as it is installed in the vehicle to ensure the integrity of both the glazing and its surrounding structure. This means that glazing in vehicle doors is tested while the door is in the normal closed condition. If the door opens during the test, the vehicle would not be in compliance with the requirements.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4443OpenMr. Toshio Maeda Executive Vice President & Chief Operating Officer Nissan Research & Development, Inc. P.O. Box 8650 Ann Arbor, Michigan 48104; Mr. Toshio Maeda Executive Vice President & Chief Operating Officer Nissan Research & Development Inc. P.O. Box 8650 Ann Arbor Michigan 48104; Dear Mr. Maeda: This is in reply to your letter of June 30, 1987 asking for an interpretation of paragraph S4.1.1.36(b)(3) of Motor Vehicle Safety Standard No. 108. That paragraph specifies in pertinent part that a replaceable bulb headlamp shall be designed to conform to Section 6.1-Aiming Adjustment Test, of SAE Standard J580 AUG79 Sealed Beam Headlamp Assembly. Section 6.1.1 states that 'when the headlamp assembly is tested in the laboratory, a minimum aiming adjustment of +/-4 deg. shall be provided in both the vertical and horizontal planes.' You have asked whether the aiming adjustment is to be achieved by the headlamp assembly, or by both the headlamp assembly 'and by the headlamp when it is mounted on the vehicle.' SAE J580 applies to the design of headlamp assemblies, including the functional parts other than the headlamps, such as aiming and mounting mechanisms and hardware. The assembly may include one or more headlamps. Although the headlamp assembly is tested in the laboratory, its design must be identical to the headlamp assembly used on the vehicle. Thus, if the aiming adjustment requirement is met by the headlamp assembly in the laboratory, it should also be met when the assembly is installed on the vehicle. An individual headlamp installed on the vehicle need not meet the aiming adjustment test unless that headlamp is part of a headlamp assembly comprising only one headlamp. I hope that this answers your question. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam0841OpenMr. Richard Stevens, Cody Chevrolet, Inc., Barre-Montpelier Road, Montpelier, VT 05602; Mr. Richard Stevens Cody Chevrolet Inc. Barre-Montpelier Road Montpelier VT 05602; Dear Mr. Stevens: This is in reply to your letter of August 1, 1972, to the attention o Mr. Jerome Palisi of our White Plains, New York Office, concerning certification requirements for a vehicle which you describe and indicate will be used by a college to transport ball teams and school personnel, but will not be equipped with flashing lights or other special school bus equipment. You apparently wish to know whether you must consider this vehicle as a school bus for purposes of certification to Federal requirements.; 'School bus' is defined in the motor vehicle safety standards to mean bus 'designed primarily to carry children to and from school, but not including buses operated by common carriers in urban transportation of school children' (49 CFR 571.3). Based upon the description you provide, the NHTSA would not consider the vehicle you describe to be a school bus. For purposes of certification to Federal requirements (49 CFR Parts 567 and 568), therefore, 'gross vehicle weight rating' should not be computed under the minimum values specified for school buses. In addition, the requirement that vehicle type be inserted on the certification label should be met by inserting, 'BUS.'; This letter should not be construed to mean that the NHTSA takes position as to whether this vehicle need, under State law, conform to requirements for school buses. The State must determine the scope and application of its own laws.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2867OpenMr. Robert B. Kurre, Director of Engineering, Wayne Corporation, P.O. Box 1447, Industries Road, Richmond, IN 47374; Mr. Robert B. Kurre Director of Engineering Wayne Corporation P.O. Box 1447 Industries Road Richmond IN 47374; Dear Mr. Kurre: This responds to your recent letter asking whether Safety Standard No 208 applies to side-facing seats in multipurpose passenger vehicle vans. You also ask to be advised of the criteria to be used for the installation of seat belts in these vehicles.; Safety Standard No. 208, *Occupant Crash Protection*, does require sid facing seats in multipurpose passenger vehicles to comply with one of the options under paragraph S4.2.2, since the side-facing seats in question would be considered designated seating positions. If a manufacturer chooses to install seat belts under one of the options of that paragraph, the seat belt assemblies must comply with Safety Standard No 209, *Seat Belt Assemblies*, and Safety Standard No. 210, *Seat Belt Anchorages*.; Safety Standard No. 210 does exempt side-facing seats from its strengt requirements, but all other requirements of the standard would be applicable. However, we strongly recommend that belt anchorages for side-facing seats be of at least equivalent strength to anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. Side-facing seats were excepted from the strength requirements specified in the standard because the forces acting on side-facing seats are different from those acting on forward or rearward facing seats and the requirements and procedures were specifically developed for these latter seats.; Please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., 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.