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: aiam0988OpenSenator Herman E. Talmadge, Senate Office Building, Washington, DC 20510; Senator Herman E. Talmadge Senate Office Building Washington DC 20510; Dear Senator Talmadge: This is in reply to your inquiry of January 16, 1973, on behalf of you constituent, Mr. Ski Bashinski. As Executive Director of the Georgia Independent Auto Dealers Association, Mr. Bashinski was concerned that the Federal Odometer Disclosure Requirements might become effective at a date earlier than that suggested in the notice of proposed rulemaking on the subject.; The regulations to which Mr. Bashinski refers were proposed by th National Highway Traffic Safety Administration on December 2, 1973, (sic) pursuant to Title IV, Odometer Requirements, of the Motor Vehicle Information and Cost Savings Act, P.L. 92-513. The effective date proposed was six months after issuance of a rule.; After reviewing the comments to its proposal, the NHTSA issued th Odometer Disclosure Requirements as a final rule on January 31, 1973. In the light of comments indicating a need for a prompt effectiveness, the rule will go into effect March 1, 1973. The other provisions of Title IV went into effect by operation of law on January 18, 1973, and require the assistance of the disclosure statement if they are to be fully effective.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4162OpenThe Honorable Edward F. Reilly, Jr., Kansas Senate, 430 Delaware Street, Leavenworth, KS 66048; The Honorable Edward F. Reilly Jr. Kansas Senate 430 Delaware Street Leavenworth KS 66048; Dear Mr. Reilly: Thank you for your letter enclosing correspondence from Mr. Dennis D Furr of Lansing, Michigan.; As we understand his letter, Mr. Furr contacted you to express hi concern about a Michigan state law which permits loading school buses up to 110 percent of the number of persons for which the bus has a rated seating capacity. He believes that installation of safety belts in school buses would reduce the likelihood that excessive numbers of children would be carried on each school bus seat.; You asked for information on Mr. Furr's suggestion for school bu safety belts. I am pleased to explain the two sets of regulations we have for school buses, both of which are relevant to school bus seating accommodations. Before I begin, I would like to note that in July 1985, we responded to an inquiry on Mr. Furr's behalf from U.S. Senator Donald W. Riegle, Jr., asking about requirements limiting school bus passenger capacities. In our response, we explained how manufacturers currently determine the passenger capacities of their school buses and that we know of no safety problem related to their calculations. A copy of our letter is enclosed for your information.; As explained in our letter to Senator Riegle, the first set o regulations we have for school buses, issued under the authority of the National Traffic and Motor Vehicle Safety Act, includes our motor vehicle safety standards which apply to the manufacture and sale of new school buses. Some of Mr. Furr's concerns involve one of those safety standards, Standard No. 222, *School Bus Passenger Seating and Crash Protection*, which specifies requirements for safety belts in small school buses. Standard No. 222 currently does not require safety belts for passengers in large school buses (those with gross vehicle weight ratings greater than 10,000 pounds) because large school buses are already required to provide high levels of protection to passengers through a concept called 'compartmentalization.' Compartmentalization requires that the interior of large buses be improved so that children are protected without the need to fasten safety belts. The seating improvements include higher and stronger seat backs, additional seat padding, and better seat spacing and performance. Our safety standards do require safety belts for passengers in smaller school buses since those buses do not offer the same protection as that provided by compartmentalization.; In his letter to you, Mr. Furr appears to be primarily concerned wit overloaded school buses and believes that safety belts would prevent schools from overcrowding school bus bench seats. We believe that this rationale for safety belts does not warrant a Federal requirement for belts on large school buses, since large school buses offer substantial protection to passengers and safety belts per se will not prevent users from overcrowding their buses. Thus, requiring safety belts in large school buses under Federal law would not assuredly lessen overcrowding of buses, and any possible improvement in seating accommodations would not be achieved.; On the other hand, we do not prevent States and local school district from ordering safety belts on their large school buses if they wish to do so. Thus, States may order school buses with safety belts if they believe this would reduce the likelihood that school buses would be overloaded. Issues relating to safety belts in large school buses are discussed in NHTSA's publication entitled, 'Safety Belts on School buses,' June 1985. I have enclosed a copy of the report for your information.; Our second set of regulations for school buses, issued under th highway Safety Act, consists of recommendations to the States for operating their school buses and applies to Federal funding of State highway safety programs. Those recommendations are found in Highway Safety Program Standard No. 17, *Pupil Transportation Safety* (copy enclosed, which Mr. Furr refers to as 'Federal Standard 17.' This 'standard,' or guideline, recommends that States provide seating accommodations of minimum specified dimensions for each school bus occupant and that States coordinate seating plans to eliminate standees. To reiterate, however, Program Standard No. 17 is a guideline for the States and its adoption is determined by the States. We have no reason to believe that Michigan has not evaluated thoroughly its pupil transportation needs in determining whether to implement the standard's recommendations.; I hope this information is helpful. Please let me know if we can be o further assistance.; Sincerely, Diane K. Steed |
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ID: aiam4539OpenMr. Earl Dahl The Goodyear Tire & Rubber Co. Akron, OH 44316-0001; Mr. Earl Dahl The Goodyear Tire & Rubber Co. Akron OH 44316-0001; "Dear Mr. Dahl: This responds to your letter of June 1, 1988, seekin an interpretation of 49 CFR Part 574, Tire Identification and Recordkeeping. Specifically, you asked whether Goodyear could engrave its mold for the Tire Identification Number with a style of characters that was not specifically authorized in the Notes following Figure 1 of 574.5. Note 1 to Figure 1 of Part 574 specifies only four different print types which may be used for the DOT symbol and tire identification number. The style of print that you wish to use is not one of these designated styles. Nevertheless, Note 4 to Figure 1 states that other print types will be permitted if approved by the National Highway Transportation Safety Administration (NHTSA). The agency has examined the print type shown in the diagram attached to your letter and has no objections to your company printing the required information in the print type you submitted. You should be aware that in the final rule establishing Part 574 (35 FR 17257, November 10, 1970), NHTSA explained that the reason for specifying only four print types which would be acceptable without advance agency approval was to ensure that the information would be easily readable by all persons. The print type that you submitted is easily readable and thus satisfies our concerns in that regard. Accordingly, NHTSA approves your print type. Sincerely, Erika Z. Jones Chief Counsel "; |
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ID: aiam2814OpenMr. E. M. Ryan, Chief Design Engineer, Ward Industries, Inc., P.O. Box 849, Highway 65 South, Conway, AR 72032; Mr. E. M. Ryan Chief Design Engineer Ward Industries Inc. P.O. Box 849 Highway 65 South Conway AR 72032; Dear Mr. Ryan: This responds to your April 27, 1978, letter asking whether a sampl certification label that you submitted complies with the National Highway Traffic Safety Administration's (NHTSA) Part 567, *Certification*.; Military vehicles are exempted from compliance with Federal safet standards. Therefore, the application of the safety standards to these vehicles is a matter of contract between a manufacturer and the military. Since the NHTSA does not mandate Federal safety standards for these vehicles, it is not necessary to put certification labels on them. If you choose to include a label with a vehicle, the label would not be required to comply with any Federal regulations.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0829OpenMr. J. W. Kennebeck, Manager, Safety & Development, Volkswagen of America, Inc., Englewood Cliffs, NJ 07632; Mr. J. W. Kennebeck Manager Safety & Development Volkswagen of America Inc. Englewood Cliffs NJ 07632; Dear Mr. Kennebeck: This is in reply to your letter of June 26, 1972, on the subject of th conformity of the Volkswagen shoulder belt/knee bar system to the requirements of Standard No. 208. I apologize for our delay.; Your first question is whether the system would meet the requirement for a fully passive system under S4.1.2.1 and S4.1.3 if it were adjusted automatically and met the frontal and lateral crash protection requirements of S5.1 and S5.2 and if the vehicle conformed to Standard 216. Our reply is that a passive seat belt system of the type you describe would appear to satisfy the requirements of S4.1.2.1 and S4.1.3. It would also, however, be required to meet the requirements of S4.5.3. We cannot determine from your description whether the system is capable of fitting the range of occupants specified in S7.1, as required by S4.5.3.3.; Your second question concerns that possibility that the system could b used, with the shoulder belt either active or passive, to meet the second or third option for passenger cars manufactured between August 15, 1973, and August 15, 1975. You point to two variances between the Volkswagen system and the system contemplated by these options. S4.1.2.2 requires the installation of a Type 1 seat belt, whereas the Volkswagen system contains only a shoulder belt and a knee bar. S4.1.2.3 specifies either a Type 1 or a Type 2 seat belt assembly, neither of which is found in the Volkswagen system. It is our opinion that these variances are such that an amendment of the standard would be required to permit the use of the Volkswagen system under either S4.1.2.2 or S4.1.2.3.; With reference to both the passive system discussed in your firs question and a petition for rulemaking in connection with your second, we are particularly concerned with the actual crash performance of a single diagonal belt restraint as opposed to the Type 1 or Type 2 belts permitted in Standard No. 208. The injury criteria presently included in Standard No. 208 may not differentiate between restraint systems with good crash force distribution, such as the air cushion, and those such as the single diagonal belt which could poorly distribute loads on real human occupants. Accordingly, we would appreciate your sending us accident data describing experience with the European-type single diagonal belt.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam3706OpenMr. C. J. Johnston, Manager, Product Reliability, The BF Goodrich Company, Tire Group, 500 South Main Street, Akron, OH 44318; Mr. C. J. Johnston Manager Product Reliability The BF Goodrich Company Tire Group 500 South Main Street Akron OH 44318; Dear Mr. Johnston: This is in response to your May 12, 1983 letter regarding the tir sidewall molding requirements of the Uniform Tire Quality Grading Standards. In that letter you indicated that, acting in reliance on statements by a NHTSA employee, your company modified certain new tire molds by deleting the numerical treadwear grade from the sidewall label, but leaving the word 'TREADWEAR' in place. NHTSA subsequently stated, in a letter to Toyo Tire Company, that if the sidewall molded label is modified, both the numerical grade and the word 'TREADWEAR' should be deleted. You also indicated that BF Goodrich is now in the process of modifying the molds again to delete the word 'TREADWEAR'.; In light of your good faith reliance on agency statements and you current efforts to conform to the policy stated in our letter to Toyo Tire Company, NHTSA will take no enforcement action regarding sidewall molding requirements for tires produced through the completion of the mold modification process.; For future reference, please be aware formal interpretations of lega requirements are issued only by this office and only in writing. To obtain an interpretation upon which reliance can be placed for purposes of making business decisions, you should direct a letter of inquiry to the Chief Counsel's Office.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0080OpenMr. R. A. Moynihan, Sales Manager - Truck Equipment, ATECO Equipment Company, Post Office Box 8741, Pittsburgh, PA 15221; Mr. R. A. Moynihan Sales Manager - Truck Equipment ATECO Equipment Company Post Office Box 8741 Pittsburgh PA 15221; Dear Mr. Moynihan: This is in further reply to your letter to Mr. Slagle dated March 8 1968, in which you ask for information as to your company's responsibility under the National Traffic and Motor Vehicle Safety Act and regulations issued pursuant to the Act.; As I understand the description of the modification your company make to trucks the only standard now in effect that is applicable is Standard No. 205, the glazing standard. Therefore, the glass that you install in place of the original glass in the truck cab would have to comply with this standard.; Your company might also be affected by the enclosed Advanced Notice o Proposed Rulemaking. Your particular attention is directed to Docket No. 2-12 which would, if finalized, make the standard concerning anchorage of seats (No. 207) applicable to trucks.; Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel |
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ID: aiam2547OpenMr. Dennis J. Mahr, Attorney at Law, 232 Davidson Building, Sioux City, IA 51101; Mr. Dennis J. Mahr Attorney at Law 232 Davidson Building Sioux City IA 51101; Dear Mr. Mahr: This responds to your February 23, 1977, letter asking whether For Motor Company's record keeping practices conform to the regulations of the National Highway Traffic Safety Administration (NHTSA).; Your letter refers to material allegedly destroyed by Ford pertainin to accident and recall information involving headlamp concealment devices in 1967 Mercury Cougars. The NHTSA is unable to ascertain from the information that you have submitted whether or not Ford's record keeping violates our requirements.; The NHTSA implemented on August 20, 1974, a regulation requirin manufacturers to retain for a period of 5 years records generated or acquired after August 15, 1969, concerning motor vehicle malfunctions that may be related to motor vehicle safety (49 CFR 576, *Record Retention*). Since the recall to which you refer occurred prior to this regulation, it is possible that the identified records were generated or acquired prior to the promulgation of the regulation, and therefore, the destruction of these records would not necessarily mean that Part 576 was violated.; The NHTSA has a public file concerning the headlamp concealment device referred to in your letter. This file containing 26 pages of information will be sent to you by our Technical Reference Branch under separate cover.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5282OpenMs. Lisa A. Norris P.O. Box 41 Mandeville, LA 70470; Ms. Lisa A. Norris P.O. Box 41 Mandeville LA 70470; Dear Ms. Norris: This is in reply to your letter of December 1, 1993 to Robert Hellmuth of this agency. You have written us questioning the disconnection of your original equipment center highmounted stop lamp when an aftermarket spoiler with lamp was installed on your Honda. American Honda has referred you to us, referencing an interpretation by our former Chief Counsel, Paul Jackson Rice. I enclose a copy of Mr. Rice's letter of August 31, 1990, to David Holscher which sets forth the agency's views on this subject. These views remain our position. The disconnecting of your lamp appears permitted under Federal Motor Vehicle Safety Standard No. 108 according to this interpretation. Because Federal authorities do not interpret the laws of the individual States, we are unable to comment on the Louisiana provisions that you paraphrase, except to note that 'tail lights', as you refer to them, are not 'stop lamps' under Standard No. 108. Taillamps are another item of lighting equipment and have no relevance to the wiring of the center highmounted stop lamp. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam5328OpenMr. Perry McGlothan Quality Assurance Test Specialist Century Products Company 9600 Valley View Road Macedonia, OH 44056; Mr. Perry McGlothan Quality Assurance Test Specialist Century Products Company 9600 Valley View Road Macedonia OH 44056; Dear Mr. McGlothan: This responds to your letter to me about the hea impact protection and protrusion limitation requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 213, Child Restraint Systems. We received under separate cover the three child seats you sent for illustration purposes, samples of Models 4560, 4590 and the STE 1000. You discuss in your letter a new method you would like to use to attach the head impact protection foam to the child restraint shell. The foam would be attached to the shell by means of two push-in pins, each 1/2 inch in length and with a 3/4 inch diameter head, as distinguished from the padding being glued to the shell as in the past. You stated that this change would better secure the foam padding to the shell and help your manufacturing process. You asked us whether the new method would meet the head impact protection requirement of S5.2.3 (for restraints recommended for children weighing less than 20 pounds) and the protrusion limitations of S5.2.4. As you know, the National Traffic and Motor Vehicle Safety Act establishes a self-certification system under which manufacturers are responsible for ensuring that their products comply with all applicable FMVSSs. We do not approve, endorse, or give assurances of compliance of any product. NHTSA may examine the manufacturer's certification in the course of any enforcement action. In response to manufacturers' requests for interpretations of the FMVSS's, we try, to the extent possible, to provide information that will help them make their determinations of compliance. However, these responses are based on information provided by the manufacturer, and is subject to the findings of actual compliance testing by the agency. Should the agency, in the future, examine production units of these models and detect an apparent noncompliance or defect, those results will control. You first inquire, 'Please advise as to compression deflection,' which we understand as asking whether S5.2.3.2 would permit you to secure the foam with the pins. S5.2.3.2 states that each system surface, except for protrusions that comply with S5.2.4, which is contactable by a dummy head must be covered with slow recovery, energy absorbing material with specified characteristics. As explained in the next paragraph, the pins we examined appear to satisfy S5.2.4. Further, the pins might not be contactable by the dummy head in Standard 213's dynamic test. However, whether they are contactable can only be determined in the standard's dynamic test. S5.2.4 requires that any portion of a rigid structural component within or underlying a contactable surface, or any portion of a child restraint system surface that is subject to S5.2.3 shall meet specified limits on height and radius of exposed edge. Based on our visual inspection, the pins we saw appear to be within those limits. Again, however, the Vehicle Safety Act places the responsibility for determining compliance in the first instance on you, the manufacturer of the child restraint. We still have the three seats that you sent us. We plan to dispose of them unless we hear from you. I hope this information is helpful to you. Should you have any further questions or need further information, please feel free to contact Walter Myers of this office at this address or at (202) 366-2992. Sincerely, John Womack Acting 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.