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 |
|---|---|
ID: aiam2284OpenMr. W. G. Milby, Staff Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Staff Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This is in response to your April 14, 1976, letter concerning th meaning of the effective dates of Federal motor vehicle safety standards.; You are correct in your understanding that a vehicle's date of sale i irrelevant to a determination of which standards are applicable to it. 49 CFR S 571.7(a), *Applicability*, specifies in relevant part:; >>>...each standard ... applies according to its terms to all moto vehicles or items of motor vehicle equipment the manufacture of which is completed on or after the effective date of the standard.<<<; For vehicles that you complete by mounting a body on a chassis, you ar permitted by 49 CFR S 567.5(a)(7) to treat as the time that manufacture is 'completed' for the purposes of S 571.7(a) any date no earlier than the manufacturing date of the incomplete vehicle and no later than the date of completion of final-stage manufacture, regardless of when the body or chassis was sold. Please note that you must be consistent in your choice of completion date, e.g., you may not choose one date to determine applicability of certain standards while choosing another date for other standards.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
|
ID: aiam2098OpenMr. Frank W. Bowers, Manager, Product Reliability, General Electric Company, Nela Park, Cleveland, OH 44112; Mr. Frank W. Bowers Manager Product Reliability General Electric Company Nela Park Cleveland OH 44112; Dear Mr. Bowers: This is in reply to your letter of July 8, 1975, to Ed Leysath of thi agency concerning wattage requirements for Type 1A and 2A headlamps.; Your specific question is whether the wattage specifications in Federa Motor Vehicle Safety Standard No. 108 for Type 1A and 2A headlamps are design wattages or maximum wattages.; Paragraph S4.1.1.21(b) of Standard No. 108 specifies that, 'Each Typ 1A headlamp shall be *designed* for a maximum of 50 watts. Each Type 2A headlamp shall be *designed* for a maximum of 60 watts for each filament.' (Emphasis added.) It follows, therefore, that the 50- and 60- watt values are design wattages. You are correct in your interpretation that a tolerance of approximately 7.5% applies to these values, and that an ampere value of 4.20 for a 50-watt filament and 5.02 for a 60-watt filament is permitted. The 7.5% tolerance as you know is the average actual maximum wattage (as opposed to design wattage) rating of headlamps listed in Table 2 of SAE Standard J573 as determined by multiplication of the maximum amperage times the design volts.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
|
ID: aiam2282OpenMr. W. G. Milby, Staff Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Staff Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This is in response to your April 14, 1976, letter concerning th meaning of the effective dates of Federal motor vehicle safety standards.; You are correct in your understanding that a vehicle's date of sale i irrelevant to a determination of which standards are applicable to it. 49 CFR S571.7(a), *Applicability*, specifies in relevant part:; >>>...each standard ...applies according to its terms to all moto vehicles or items of motor vehicle equipment the manufacture of which is completed on or after the effective date of the standard.<<<; For vehicles that you complete by mounting a body on a chassis, you ar permitted by 49 CFR S567.5(a)(7) to treat as the time that manufacture is 'completed' for the purposes of S571.7(a) any date no earlier than the manufacturing date of the incomplete vehicle and no later than the date of completion of final-stage manufacture, regardless of when the body or chassis was sold. Please note that you must be consistent in your choice of completion date, e.g., you may not choose one date to determine applicability of certain standards while choosing another date for other standards.; Sincerely, Frank A Berndt, Acting Chief Counsel |
|
ID: aiam0294OpenMr. Francis M. Coffey, Jr., Automotive Safety Engineering, General Motors Engineering Staff, General Motors Technical Center, Warren, MI, 48090; Mr. Francis M. Coffey Jr. Automotive Safety Engineering General Motors Engineering Staff General Motors Technical Center Warren MI 48090; Dear Mr. Coffey: This is in reply to your letter of February 12, 1971, to Mr. R. A Diaz, Acting Associate Administrator, concerning an error in Federal Motor Vehicle Safety Standard No. 108.; SAE Standard J954 referenced in Table III is an error, this should b J945, and will be corrected in a future amendment.; Thank you for calling this to our attention. Sincerely, Roger H. Compton, Director, Office of Operating Systems Motor Vehicle Programs; |
|
ID: aiam3710OpenMr. Wayne T. Halbleib, Assistant Attorney General, Office of the Attorney General, Supreme Court Building, 101 North Eighth Street, Richmond, VA 23219; Mr. Wayne T. Halbleib Assistant Attorney General Office of the Attorney General Supreme Court Building 101 North Eighth Street Richmond VA 23219; Dear Mr. Halbleib: This is in response to your letter of May 25, 1983 in which you aske whether the provisions on the back of Virginia's Certificate of Title are sufficient to satisfy the odometer mileage disclosure requirements contained in 49 CFR Part 580. The provisions are sufficient. Virginia's certificate of Title may therefore be used in lieu of a separate Federal odometer statement.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam0890OpenMr. Olav Kviteng, A/S Raufoss Ammunisjonsfabrikker, 2831 Raufoss, Norway; Mr. Olav Kviteng A/S Raufoss Ammunisjonsfabrikker 2831 Raufoss Norway; Dear Mr. Kviteng: This is in reply to your letter to the Docket Section of September 28 1972, on the subject of the test speeds required for the corner impact tests of Motor Vehicle Safety Standard No. 215, Exterior Protection.; The correct impact speed in corner tests is 3 m.p.h. at both front an rear. The test speed was reduced to this level by a notice of rulemaking published June 22, 1972, and has not been subsequently changed. The publication sent you by the Government Printing Office, in which the speed is erroneously given as 5 m.p.h. for the front and 4 m.p.h. for the rear, is not an official publication and does not affect the requirement.; We regret the error. The test speed will be corrected in futur supplements.; Truly yours, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam3575OpenCarolyn L. Carter, Esq., The Legal Aid Society of Cleveland, Law Reform Office, 1223 West Sixth Street, Cleveland, OH 44133; Carolyn L. Carter Esq. The Legal Aid Society of Cleveland Law Reform Office 1223 West Sixth Street Cleveland OH 44133; Dear Ms. Carter: This is in response to your letter of May 4, 1982, concerning whethe the odometer disclosure form on the Ohio certificate of title has been approved for use in lieu of the Federal odometer disclosure statement. The odometer disclosure statement on the Ohio certificate of title has been approved by the agency for use in lieu of the Federal form.; As requested in your letter, I am enclosing a copy of the agency' letter to the Ohio Bureau of Motor Vehicles approving their form as a substitute for the Federal form.; If you have any further questions, please do not hesitate to write. Sincerely, David W. Allen, Assistant Chief Counsel |
|
ID: aiam2729OpenMaj. Gen. James A. Richardson III, 4551 LaSalle Avenue, Alexandria, VA 22304; Maj. Gen. James A. Richardson III 4551 LaSalle Avenue Alexandria VA 22304; Dear General Richardson: This is in response to your letter of December 12, 1977, concerning th preemption of State bumper standards by the Federal bumper standard (49 CFR Part 581, *Bumper Standard*).; Section 110 of the Motor Vehicle Information and Cost Savings Act (Pub L. 92-513) states that, until a Federal bumper standard takes effect, State bumper standards which were either in effect or promulgated prior to the effective date of the Act, shall be permitted to remain in force. Once the Federal bumper standard (Part 581) becomes effective, however, all State bumper standards applicable to the same aspect of performance as the Federal standard will be preempted.; Currently, the mandatory date for implementation of Part 581 i September 1, 1978. However, on June 20, 1977, the National Highway Traffic Safety Administration published a Federal Register notice (42 FR 31162) giving manufacturers the discretion to begin meeting the provisions of Part 581 prior to September 1, 1978. Once a manufacturer makes a decision to meet Part 581, it no longer has a responsibility to meet the currently effective bumper requirements of Standard No. 215, *Exterior Protection*. For such a manufacturer Part 581 would have taken effect and it would be obliged to meet the performance level the standard prescribes.; For purposes of preemption, once a manufacturer elects to meet th requirements of Part 581, that standard is in effect as to that manufacturer, and any State bumper standard applicable to the same aspect of performance as Part 581 is preempted as it applies to the vehicles he manufacturers.; Part 581 would not, however, be considered effective as to vehicle which continue to meet only the requirements of Standard 215. State bumper standards, thus, would not be preempted for purposes of application to those vehicles. Of course, all State bumper standards applicable to the same aspect of performance as Part 581 will be totally preempted after September 1, 1978, since at that time Part 581 becomes effective for all passenger cars.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
ID: aiam2857OpenMr. D. L. Haines, The B. F. Goodrich Company, Engineered Systems Division, P.O. Box 340, Troy, OH 45373; Mr. D. L. Haines The B. F. Goodrich Company Engineered Systems Division P.O. Box 340 Troy OH 45373; Dear Mr. Haines: This responds to B. F. Goodrich's August 2, 1978, question whether th specified temperature for brake burnish in S6.1.8.1 of Standard No. 121, *Air Brake Systems*, should be maintained by reducing maximum vehicle speed during snubs even if the reduced maximum speed does not appear among the snub conditions listed in Table IV of S6.1.8.1.; The answer to your question is yes. The snub conditions listed in Tabl IV represented the agency's best estimate of appropriate speeds for obtaining the specified burnish temperature, given the state-of- the-art of brake technology when the standard was issued. If you have under development a brake design that achieves the specified burnish temperature at a lower speed, it would be correct to reduce vehicle speed below the 40-mph level specified in Table IV to achieve and maintain that temperature.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
ID: aiam3604OpenMr. R. H. Zelinski, Vice President, Corporate Engineering, Zimmer Corporation, P.O. Box 2127, Pompano Beach, FL 33061; Mr. R. H. Zelinski Vice President Corporate Engineering Zimmer Corporation P.O. Box 2127 Pompano Beach FL 33061; Dear Mr. Zelinski: Thank you for your letter of August 6, 1982, to the Administrato asking whether there is 'any blanket waiver of standards solely based on a small production of vehicles.'; You are correct that no such waiver exists. Even a single automobil manufactured for use on the public roads must meet all applicable Federal motor vehicle safety standards unless exempted by the Administrator under the provisions of Part 555. A manufacturer whose total motor vehicle production in the year preceding filing of his petition does not exceed 10,000 units is eligible to apply for an exemption of up to three years on a hardship basis. Any manufacturer of motor vehicles may apply for an exemption of up to two years on the three remaining bases that you mention but the exemption extends only to a maximum of 2500 vehicles in any 12-month period that the exemption is in effect.; Under the original exemption authority, in effect from 1968 to 1971 exemptions were available on a hardship basis and the threshold of eligibility was 500 units.; Sincerely, Frank Berndt, 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.