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: aiam1405OpenJames B. Steward, Esq., Bridges and Collins, Bridges Building, 701 Teal Lake Avenue, Negaunee, MI 49866; James B. Steward Esq. Bridges and Collins Bridges Building 701 Teal Lake Avenue Negaunee MI 49866; Dear Mr. Steward: In reply to your request of January 30, 1974, I am enclosing a copy o the regulation issued to implement the odometer disclosure requirements of Public Law 92.513.; Although there are a variety of ways to determine whether a vehicle' actual mileage is greater than shown on the odometer, I know of only one method to establish the exact amount by which the indicated mileage has been exceeded: the testimony of a witness who knew the exact mileage on the car at the time the odometer was changed and who knows the accuracy of the odometer's performance after the change.; I would be most interested to learn of the progress of your action. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam4607OpenM. Iwase, General Manager Technical Information Dept. Koito Mfg. Co., Ltd. Shizuoka Works 500, Kitawaki Shimizu-shi, Shizuoka-ken Japan; M. Iwase General Manager Technical Information Dept. Koito Mfg. Co. Ltd. Shizuoka Works 500 Kitawaki Shimizu-shi Shizuoka-ken Japan; Dear Mr. Iwase: This is in reply to your letter of March 20, l989 asking for an interpretation of Motor Vehicle Safety Standard No. l08 as it applies to the location of the license plate lamp on motor vehicles. You noted the language in Tables II and IV of Standard No. l08 specifying that the lamp is to be located 'at rear license plate, to illuminate the plate from the top or sides,' for vehicles other than motorcycles. The requirement for motorcycles (Table IV) is simply that it be located 'at rear license plate.' You have asked for confirmation that, except on motorcycles, the license plate lamp shall not illuminate the plate from the bottom. Your interpretation is correct. The rationale for the requirement is that in a location other than at the bottom, the license plate lamp is less likely to be obstructed by snow or mud. I hope that this answers your question. Sincerely, Stephen P. Wood Acting Chief Counsel /; |
|
ID: aiam4312OpenMr. Robert R. Shapro, Vice President, Transportation Specialist, Inc., 512 Cave Road, Nashville, TN 37210; Mr. Robert R. Shapro Vice President Transportation Specialist Inc. 512 Cave Road Nashville TN 37210; Dear Mr. Shapro: This list responds to your request for 'the fact sheet concernin certification as required' by 49 CFR Parts 567 and 568. You describe your company as a 'multistage manufacturer,' and ask how your company can become certified 'to manufacture or alter vehicles in accordance with the code of Federal regulation.' I regret the delay in responding to your request.; First, please be aware that the National Highway Traffic Safet Administration (NHTSA) has authority to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. The NHTSA does not approve vehicles or equipment, nor do we endorse any commercial products. Instead, the National Traffic and Motor Vehicle Safety Act establishes a certification process under which each manufacturer must certify that its product meets agency safety standards, or other applicable standards. Periodically, NHTSA tests whether vehicles or equipment comply with these standards, and may investigate alleged safety-related product defects.; As you request, I enclose a copy of 49 CFR Part 567, *Certification* and Part 568, *Vehicles Manufactured in Two or More Stages*. Also, for your information, I enclose an information sheet that may be of interest to you if you are new to motor vehicle and motor vehicle equipment manufacture.; Please note that there is no requirement that a company be 'certified before it can manufacture or alter vehicles. 49 CFR Part 566 does require that if a company begins to manufacture motor vehicles subject to any of the Federal safety standards, it must submit information identifying itself and its products to NHTSA not later than 30 days after it begins manufacture.; I hope you find this information helpful. Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam1110OpenMr. William Eriksen, Anderson-Alford, Seventh at D Streets, P.O. Box AA, Eureka, CA; Mr. William Eriksen Anderson-Alford Seventh at D Streets P.O. Box AA Eureka CA; Dear Mr. Eriksen: This is in reply to your letter of April 3, 1973, inquiring whethe there are licenses and forms that you must obtain before you may install old truck bodies on new trucks.; Persons who install used truck bodies on new trucks are generall considered to be 'final-stage manufacturers' under NHTSA Certification regulations (49 CFR 567, 568). These regulations require final-stage manufacturers of multi-stage vehicles to certify the conformity of such vehicles to all applicable motor vehicle safety standards. Certification is accomplished by affixing a label to the vehicle. The requirements for both the location and content of the label are contained in the Certification regulations, and you may obtain copies of these regulations as indicated on the enclosed, 'Where to Obtain Motor Vehicle Safety Standards and Regulations'.; There are no licensing requirements, nor specified forms you mus complete before you undertake these manufacturing operations. However, the NHTSA does have requirements, (Part 566, 'Manufacturer Identification', copy enclosed) that require you to submit certain information regarding your company within 30 days after commencing manufacture.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam4742OpenJoseph R. Wheeler, Esq. P.O. Box 2808 424 Church St., Suite 2900 Third National Financial Center Nashville, TN 37219; Joseph R. Wheeler Esq. P.O. Box 2808 424 Church St. Suite 2900 Third National Financial Center Nashville TN 37219; "Dear Mr. Wheeler: This is in response to your letter to Kennet Weinstein of my staff requesting information about actions by the Secretary of Transportation pursuant to Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection (49 CFR 571.208). More specifically, you noted that S4.1.4.1 of Standard No. 208 states that, 'Except as provided in S4.1.5 and another section not relevant to your inquiry , each passenger car manufactured on or after September 1, 1989 shall comply with the automatic restraint requirements .' S4.1.5 of Standard No. 208 provides that: 'If the Secretary of Transportation determines, by not later than April 1, 1989, that state mandatory safety belt usage laws have been enacted that meet the criteria specified in S4.1.5.2 and that are applicable to not less than two-thirds of the total population . . ., the automatic restraint requirements will not go into effect .' You asked whether the Secretary ever made a determination under S4.1.5 regarding State safety belt use laws. The answer is no. Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so. Because no determination was made under S4.1.5, the automatic restraint requirements are now in effect for all passenger cars. This letter expresses no opinion about the implications under Tennessee law of the absence of a determination by the Secretary of Transportation regarding any State's safety belt law. Sincerely, Paul Jackson Rice Chief Counsel"; |
|
ID: aiam3087OpenMr. Ron Bechtel, Halliburton Services, Drawer 1431, Ducan, Oklahoma 73533; Mr. Ron Bechtel Halliburton Services Drawer 1431 Ducan Oklahoma 73533; Dear Mr. Bechtel: This is in response to your letter of May 1, 1979, requesting a interpretation of the definition of 'incomplete vehicle' contained in Federal Motor Vehicle Safety Standard No. 115, and in confirmation of your subsequent telephone conversations with Mr. Schwartz of my office.; The term 'incomplete vehicle' is defined in S3 of the standard to mea 'an assemblage consisting, as a minimum, of frame and chassis structure, power train, steering system, suspension system, and braking system, to the extent that those systems are to be part of the completed vehicle, that requires further manufacturing operations, other than the addition of readily attached components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed trailer.; You are correct in saying that most of the components listed in th definition are not meant to be part of a trailer. Consequently, an incomplete Trailer would consist of only those components, such as a frame, listed in the definition which are meant to be part of the completed trailer. The outfitting of an incomplete trailer for a specific purpose would not be sufficient to make Halliburton Serviced responsible for assigning the vehicle identification number.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam1540OpenMr. John W. Kourik, Wagner Division, Wagner Electric Corporation, 11444 Lackland Road, St. Louis, MO 63141; Mr. John W. Kourik Wagner Division Wagner Electric Corporation 11444 Lackland Road St. Louis MO 63141; Dear Mr. Kourik: This responds to your March 12, 1974, request for interpretation of th volume requirements for service brake chambers in S5.1.2.1 and S5.2.1.2 of Standard No. 121, *Air Brake Systems*:; >>>S5.1.2 Total service reservoir volume shall be at least eight time the combined volume of all service brake chambers at maximum travel of the pistons or diaphragms.<<<; You also requested the addition of language equating brake chambe volume with brake chamber displacement, based on nominal effective area and rated stroke. In testing for compliance with S5.1.2.1 and S5.2.1.2, the NHTSA will accept a manufacturer's published 'rated volume' of the brake chamber with the piston or diaphragm at maximum travel. This means that the manufacturer may specify the full stroke of the piston or diaphragm and compute the 'rated volume' based on the designed volume of the chamber and the full stroke he has established. This volume may be somewhat larger than 'nominal brake chamber displacement' which does not necessarily account for the void ahead of the relaxed diaphragm or piston, the so-called 'pre-fill volume'. This volume must be included because it must be pressurized along with the displaced volume.; In the absence of manufacturer's published ratings, the NHTSA wil measure the brake chamber volume with the push rod at maximum stroke.; Your request to add explanatory language to the standard of th measurement technique is denied as unnecessary in view of this interpretation.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
|
ID: aiam5503OpenMr. Harry C. Gough, P.E. State of Connecticut Department of Motor Vehicles 60 State Street Wethersfield, CT 06161; Mr. Harry C. Gough P.E. State of Connecticut Department of Motor Vehicles 60 State Street Wethersfield CT 06161; "Dear Mr. Gough: This responds to your letter to this office askin whether the retroreflective tape required to outline school bus emergency exits can, in the case of the rear emergency door, be placed on the door itself. The short answer is no. You stated that the State of Connecticut requires that school bus bumpers be black. You further stated that one school bus manufacturer supplied buses with the bottom piece of the retroreflective tape installed on the rear bumper. You then noticed that a number of school buses from a different manufacturer had the bottom part of the tape installed on the door itself. You asked whether the language of S5.5.3 of Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus emergency exits and window retention and release, permitted the installation of the retroreflective tape on the door itself. Paragraph S5.5.3 of FMVSS No. 217 (49 CFR 571.217) provides: Each opening for a required emergency exit shall be outlined around its outside perimeter with a minimum 3 centimeters wide retroreflective tape, either red, white, or yellow in color, . . . This requirement was imposed by amendment to FMVSS No. 217 promulgated by a final rule published in the Federal Register on November 2, 1992 (57 FR 49413). In discussing this requirement in the preamble portion of the final rule, we said at 57 FR 49421: Accordingly, the final rule requires a minimum 1 inch wide strip of retroreflective tape, either red, white, or yellow in color, to be placed around the outside perimeter of the emergency exit opening, not the emergency exit itself (emphasis added). As you may know, the buses with the tape on the emergency exit doors have been recalled by the manufacturer. For information about the recall, you can contact the bus manufacturer, Thomas Built Buses, P. O. Box 2450, High Point, NC 27261. Enclosed for your information are two interpretative letters issued by this office on related issues pertaining to the retroreflective tape requirement. See letter to Mr. Thomas D. Turner, Manager, Engineering Services, Blue Bird Body Company, dated July 7, 1993, and letter to Mr. Turner dated March 28, 1994. I hope the above information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel Enclosures"; |
|
ID: aiam1813OpenMr. Tatsuo Kato, Staff, Safety, Nissan Motor Co., Ltd., P.O. Box 1606, Englewood Cliffs, N.J. 07632; Mr. Tatsuo Kato Staff Safety Nissan Motor Co. Ltd. P.O. Box 1606 Englewood Cliffs N.J. 07632; Dear Mr. Kato: #This is in reply to your letter of January 21, 1975 requesting an opinion on whether either Federal Standard No. 109 or No. 119, or both, apply if Nissan equips a truck with a passenger car tire size (6.95 x 14-4PR). #Standards Nos. 109 and 119 apply to the tire only. consequently, the manufacturer of the tire has presumably made determination as to which standard applied when he manufactured the tire. There is no prohibition in the Federal safety standards to the use of a 'passenger car tire' on a truck. The truck manufacturer should, of course, ensure that the tire has a sufficient load carrying capacity for safe use on a truck. #Yours truly, #Richard B. Dyson, Assistant Chief Counsel; |
|
ID: aiam0701OpenNorman W. Quinn, Esq., Messrs,(sic) Nickell, Quinn & Mah, 2131 Seattle First National Bank Building, 1001 Fourth Avenue, Seattle, WA 98154; Norman W. Quinn Esq. Messrs (sic) Nickell Quinn & Mah 2131 Seattle First National Bank Building 1001 Fourth Avenue Seattle WA 98154; Dear Mr. Quinn: This is in reply to your letter of May 5 on behalf of your client Le Ross. Mr. Ross has developed a motor vehicle deceleration warning system that, as described by you, activates two amber lights on the rear of a vehicle. Your letter indicate that these lamps would be incorporated into a vehicle back-up lamp system and that Mr. Ross envisions his system as an aftermarket accessory item rather than as new vehicle original equipment. You state your understanding that Motor Vehicle Safety Standard No. 108 would not preclude marketing the system as an aftermarket accessory, and that back-up lamps are required to be white in color. You ask our advice whether Standard No. 108 prohibits amber lamps in the back-up lighting system and, if so, whether a proposal for amendment of the Standard to allow the system would be feasible.; Standard No. 108 would in certain instances preclude the aftermarke sale of an amber deceleration warning system incorporated into a back-up lamp system. Standard No. 108 as of January 1, 1972, does cover certain aftermarket equipment items, and in some instances would preclude the sale of a back-up light system with amber lamps. Lighting equipment manufactured on or after that date as replacement for similar equipment on vehicles manufactured on or after January 1, 1972, must meet Standard No. 108 which, as you have noted, requires that the color of the back-up lamps be white. Federal law would not preclude sale of this system for use on motor vehicles manufactured before January 1, 1972, or purchase of an amber system by the owner of a vehicle manufactured after that date if he wished to change over from a white to amber system. As a practical matter, however, I believe That(sic) virtually every State has a requirement that back-up lamps be white, and that a back-up light with amber bulbs or lenses would be forbidden. Standard No. 108 would not preclude sale of the Ross System as a separate lighting device. I do not know what position the States would take on such a matter.; Our research contracts on deceleration warning system indicate tha further development and testing under field conditions is necessary before specific proposals can be made by NHTSA. Therefore, I do not think action on a proposal by Mr. Ross would be feasible at this time, though we would welcome his comments to our Docket 69-19 as a comment to be considered in future rulemaking on this subject.; Yours truly, Richard B. Dyson, Assistant 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.