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
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ID: aiam0069OpenMr. R.R. McLain,Sales Manager,Royal Brass, Inc.,442 Arlington Avenue,Fond Du Lac, Wisconsin 54935; Mr. R.R. McLain Sales Manager Royal Brass Inc. 442 Arlington Avenue Fond Du Lac Wisconsin 54935; Dear Mr. McLain:#Thank you for your letter of April 26, 1968 concerning certification of brake hoses. Hydraulic brake hoses for use in passenger cars and multipurpose passenger vehicles manufactured after January 1, 1968 must comply with Federal Motor Vehicles Safety Standard No. 106, Hydraulic Brake Hoses - Passenger Cars and Multipurpose Passenger Vehicles.#At the time of delivery of the completed brake hose assembly to a distributer or dealer the manufacturer of the completed brake hose assembly must certify that it complies with the applicable standard. In the case of equipment such as the brake hose assembly the certification may be in the form of a label or tag on the completed brake hose assembly delivered.#For your information I have enclosed a copy of the Federal Motor Vehicle Safety Standards, the notice published in the *Federal Register* concerning certification and a copy of the National Traffic and Motor Vehicle Safety Act of 1966. Particular attention should be paid to the sections 108 and 114 of the Act.#I hope this letter and the enclosures are adequately responsive to your questions. #Sincerely,Robert M O'Mahoney,Assistant Chief Counsel; |
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ID: aiam2054OpenMr. K. Nakajima, Director/General Manager, Factory Representative Office, Toyota Motor Sales, U.S.A., Inc., 1099 Wall Street, West Lyndhurst, NJ 07071; Mr. K. Nakajima Director/General Manager Factory Representative Office Toyota Motor Sales U.S.A. Inc. 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima: This is in response to your letter of July 30, 1975, in which you aske whether the uniform tire quality grading requirements for furnishing information to prospective purchasers of vehicles apply to prospective purchasers of vehicles other than passenger cars that may be equipped with passenger car tires. This was asked in light of the fact that the tire quality grading rule itself applies to tires manufactured for use on passenger cars.; We do not consider that the requirements of S 575.6(a) and (c) regarding the furnishing of consumer information to motor vehicle buyers and prospective purchasers, apply to the sale of trucks or other non-passenger- car vehicles where uniform tire quality grading information is concerned.; We recognize that the language of the regulation may not be entirel clear in this regard, and are considering an interpretive amendment to clarify it.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2541OpenMr. R. A. Bynum, Supervisor, Pupil Transportation Service, Commonwealth of Virginia, State Department of Education, Richmond, VA 23216; Mr. R. A. Bynum Supervisor Pupil Transportation Service Commonwealth of Virginia State Department of Education Richmond VA 23216; Dear Mr. Bynum: This responds to your February 18, 1977, letter asking whether Standar No. 222, *School Bus Passenger Seating and Crash Protection*, permits the use of a two-passenger front-row seat with a corresponding two-passenger front-row restraining barrier. Secondly, you ask whether the State of Virginia can require the use in joints of discrete fasteners and welding, and not adhesives, without conflicting with the requirements of Standard No. 221, *School Bus Body Joint Strength*. Finally, you ask who must certify that a vehicle complies with Standard No. 105, *Hydraulic Brake Systems*.; The NHTSA has issued an interpretation allowing the use of a two passenger front-row seat with a two-passenger restraining barrier. This can be accomplished by the use of a two-passenger seat cushion and a three-passenger seat back as you suggest. I am enclosing a copy of the NHTSA interpretation for your information.; Regarding your second question concerning the use of adhesives in bu body joints, the Federal bus body joint standard requires only that joints meet a specified strength requirement. The NHTSA does not require any particular type of joint construction. Therefore, the purchaser and manufacturer can decide upon any method of joint construction as long as the joint meets Federal strength specifications.; Your final question asks who must certify that a small school bu (under 10,000 pounds) is in compliance with Standard No. 105, *Hydraulic Brake Systems*. To assign responsibility for the certification of multi-stage vehicles, NHTSA has issued Part 568, *Vehicles Manufactured in Two or More Stages* (enclosed). The manufacturer of an 'incomplete-vehicle' (such as a cab-chassis) must provide documentation to the intermediate- and final-stage manufacturer of the vehicle on how to complete it so that it complies with all applicable standards. It is the responsibility of the final- stage manufacturer to affix a certification label unless the incomplete- or intermediate-stage manufacturer assumes this responsibility.; On a related matter concerning small school buses, it is ou understanding that school buses weighing under 10,000 pounds will be available after April 1, 1977.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5284OpenSgt. Dennis Platt, Supervisor Vehicle Safety & Equipment Section State of Utah Department of Public Safety Utah Highway Patrol 4501 South 2700 West Salt Lake City, UT 84119-5994; Sgt. Dennis Platt Supervisor Vehicle Safety & Equipment Section State of Utah Department of Public Safety Utah Highway Patrol 4501 South 2700 West Salt Lake City UT 84119-5994; Dear Sgt. Platt: This responds to your letter of December 7, 1993 requesting confirmation of a statement made by a NHTSA officer that there is no federal regulation that requires replacement of a deployed air bag. I am enclosing two letters that explain legal obligations to replace air bags which have been deployed. The first letter, dated January, 19, 1990, is to Ms. Linda L. Conrad. The second letter, dated March 4, 1993, is to Mr. Robert A. Ernst. As explained in those letters, Federal law does not require replacement of a deployed air bag in a used vehicle. In addition, there is no Federal law that prohibits selling a used vehicle with a supplemental restraint that is inoperable because of a previous deployment. However, our agency strongly encourages dealers and repair businesses to replace deployed air bags whenever vehicles are repaired or resold, to ensure that the vehicles will continue to provide maximum crash protection for occupants. Moreover, a dealer or repair business may be required by state law to replace a deployed air bag, or be liable for failure to do so. I am also enclosing a copy of the information sheet referred to in the two letters discussed above. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures; |
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ID: aiam0086OpenMiss Lucy Wissler, President, Gypsy Campers, 1601 West 190 Street, Gardena, CA 90247; Miss Lucy Wissler President Gypsy Campers 1601 West 190 Street Gardena CA 90247; Dear Miss Wissler: Thank you for your letter of May 29, 1968, in which you state that you camper conversion is not subject to the requirements of the Federal Motor Vehicle Safety Standards.; Please note the requirements for glazing in Federal Motor Vehicl Safety Standard No. 205, contained in our letter to you dated May 24, 1968. Should your modification involve installation of glazing, then these requirements would apply.; Note also Standards No. 103, 106, 107, 111, and 211, which ar applicable to a multi-purpose passenger vehicle. Your conversion of a van to a camper is conversion of a truck to a multi-purpose passenger vehicle, and therefore, requires compliance with applicable standards.; Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis, Motor Vehicle Safety Performance Service; |
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ID: aiam2111OpenMr. W.G. Milby, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W.G. Milby Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This is in response to your letter of September 23, 1975, in which yo inquire whether the emergency exit decal installations shown in photographs enclosed with your letter comply with paragraphs S5.5.1 and S5.5.2 of Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus Window Retention and Release.'; It appears from the photographs you provided that some of the emergenc exit markings may not comply with some of the requirements specified in FMVSS No. 217. Our specific comments are listed below:; 1. Figure 1 - The emergency exit marking for the rear door appears t meet the requirements. It is to be noted, however, that revised requirements for emergency exits on school buses have been proposed which may differ from the current requirements.; 2. Figures 2 and 3 - The emergency exit marking for the side push-ou windows does not appear to meet the requirements of S5.5.2. Both the seat back and the adjacent seated occupant partially obstruct the marking so it is not legible from the adjoining seat or the aisle location.; 3. Figure 4 - The emergency exit marking for the side door appears t meet the requirements.; 4. Figure 5 - The marking for the rear window emergency exit that i adjacent to a davenport type seat with unknown seating capacity appears to contain two release mechanisms (laterally spaced at each edge) and an identical marking for each latch mechanism. We cannot determine if occupants would obstruct these markings from standees if all positions in the davenport type seat were occupied.; We also question whether the instructions are complete because i cannot be determined if both latches must be released before the window can be pushed out.; 5. Figure 6 - The emergency exit marking for the transit sliding typ window appears to meet the requirements.; 6. Figure 7 - The center rear emergency door which contain instructions for unlatching the opening of the door in the form of an arrow only per the proposed amendment to FMVSS No. 217, Docket 75-3: Notice 1 does not meet the present requirements for emergency exit identification. The specific content of the emergency exit marking for school buses has not yet been finalized by this agency and we, therefore, cannot comment until a final rule on the proposal has been published in the *Federal Register*; 7. Figures 8 and 9 - The emergency exit marking for another transi sliding type window appears to meet the requirements.; It is emphasized that these comments are for your information only an are based on the contents of your photographs. This agency cannot make a final judgement concerning compliance of a bus from photographs of components. The determination of compliance or noncompliance with FMVSS No. 217 can be made only by the actual inspection and test of a complete vehicle.; I trust this information will be of assistance to you in regard to you inquiries.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4495OpenMr. Derek Nash Artech Corporation 2901 Telestar Court Falls Church, VA 22042; Mr. Derek Nash Artech Corporation 2901 Telestar Court Falls Church VA 22042; "Dear Mr. Nash: This responds to your letter to the National Highwa Traffic Safety Administration (NHTSA) and follows up on the April 1, 1988 telephone conversation with Ms. Hom of my staff in which additional information augmenting your letter was provided. I apologize for the delay in responding. In your letter, you said that you are refurbishing a type of passenger vehicle that was first produced 20 years ago. Your letter raises questions about Federal requirements for persons modifying used vehicles which I will address in the latter part of this letter and about Federal requirements for the design of the vehicle's chassis. Before I address your specific questions, I would like to provide some background information on our regulations and safety standards. NHTSA has the authority under the National Traffic and Motor Vehicle Safety Act (copy enclosed) to issue motor vehicle safety standards for new motor vehicles and items of motor vehicle equipment. Manufacturers of new vehicles or equipment must certify that their products conform to all applicable Federal motor vehicle safety standards. NHTSA also has the authority to investigate safety-related defects in motor vehicles and motor vehicle equipment. If a manufacturer or the agency determines that the manufacturer's product contains a safety-related defect, the manufacturer must notify purchasers of the product and remedy the defect free of charge. It is not clear from the information which you have provided us whether the vehicle you are refurbishing would be treated as a new or used vehicle under the Safety Act. A vehicle with a new body and new chassis would be a new vehicle required to meet the standards in effect on the day that manufacture of the vehicle is completed. A vehicle with a new body and old chassis would be a used vehicle. Section 108(a)(2)(A) of the Safety Act prohibits manufacturers, dealers, distributors and motor vehicle repair businesses (i.e., persons holding themselves out to the public as in the business of repairing motor vehicles or motor vehicle equipment for compensation) from knowingly rendering inoperative any device or element of design installed on or in a new or used motor vehicle in compliance with an applicable Federal motor vehicle safety standard. This means that any person in the above categories modifying a new or used vehicle must do so in a manner that ensures the continued compliance of the vehicle with applicable safety standards. This prohibition affects vehicles manufactured on or after January 1, l968, the date on which the first Federal safety standards became effective. For instance, a commercial business that installs a new fuel system in a passenger car manufactured on or after January 1, 1968 (the effective date of Standard No. 301) must ensure that the new system at least meets the level of safety performance required of the fuel system originally installed on the vehicle. Persons violating section 108 are subject to potential civil penalties of $1,000 per violation. In instances in which a new vehicle body is installed on an old chassis, section 108(a)(2)(A) requires that the reassembled vehicle meet the Federal safety standards that had been in effect on the date of manufacture of the vehicle. I have enclosed a copy of a January 14, 1976 letter to Mr. Tom Welland that describes generally the applicability of Federal motor vehicle safety standards to refurbished motor vehicles. Please note that the first situation referred to in the Welland letter addresses the modification of a vehicle by its owner. The prohibition in section 108(a)(2)(A) does not apply to the modifications made by vehicle owners to their own vehicles. I will now address the questions you expressly posed in your letter. Your first three questions asked: What relationship between allowable stresses in chassis members and the strength of the material is required (or customary) in the design of a passenger-carrying motor vehicle? What relationship between static and dynamic load is required (or customary) in design assumptions for a passenger-carrying motor vehicle chassis? What form or test or measurement is required (or customary) to confirm the results of the calculations? As Ms. Hom informed you, our safety standards apply to new vehicles and are performance-oriented. NHTSA has not issued any design specifications that directly establish minimum static or dynamic loads for vehicle chassis. These design parameters are established by the manufacturer independently of specific criteria set by the agency and might be available from the original manufacturer of the vehicle you are refurbishing. However, manufacturers of new vehicles are required by NHTSA to determine and specify the gross vehicle and axle weight ratings of their vehicles in the manner set forth in Title 49 of the Code of Federal Regulations, Part 567 of our regulations. I have enclosed a copy of Part 567 for your information. Chassis manufacturers must be aware, however, of the following two considerations relating to the static and dynamic load capacities of vehicles and NHTSA's regulations. First, because manufacturers of new vehicles must certify that their vehicles will perform to the requirements of all applicable Federal motor vehicle safety standards, manufacturers must ensure that chassis design is compatible with the vehicle's ability to comply. Some of our safety standards specify that the performance of requisite vehicle safety systems will be evaluated in dynamic (i.e., crash) tests which enable the agency to evaluate the synergistic effect of a range of variables on a vehicle's compliance therewith. Manufacturers of new vehicles would therefore have to ensure that the design of the chassis will have no negative effect on their vehicle's compliance with applicable safety standards. Second, as mentioned above, NHTSA has the authority to investigate safety-related defects in motor vehicles and motor vehicle equipment and to require manufacturers to recall and remedy such defects free of charge. Chassis manufacturers must therefore ensure that their products contain no safety related defects, which might well include a chassis member that is incapable of carrying loads for which it is intended. Further, the vehicle manufacturer who provides the GVWR and GAWR information required by Part 567 must ensure that the information relating to the chassis static loads is correct. On a separate matter, your letter also asked about the requirements manufacturers must meet when installing a plastic fuel tank in a motor vehicle. The standard we issued for vehicle fuel system integrity (No. 301) sets performance requirements for fuel systems in new motor vehicles. As with all our safety standards, Standard No. 301 (copy enclosed) specifies the test that the agency will use to evaluate the performance of the requisite safety system (e.g., the fuel system) on new vehicles selected for inclusion in its compliance test program. Manufacturers are not bound, however, to use the tests specified in the safety standards for evaluating the compliance of their vehicles or equipment with our standards. Instead, a manufacturer may test in any manner it chooses, so long as it can show that it has exercised due care in ensuring that its vehicles or items of equipment comply with the applicable Federal requirements. In addition to the materials described above, I have also enclosed information that provides an overview of Federal requirements applying to manufacturers of new motor vehicles and instructions on how you can obtain copies of NHTSA regulations. I hope this information is helpful. Please contact my office if you have further questions. Sincerely, Erika Z. Jones Chief Counsel Enclosures"; |
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ID: aiam3350OpenMr. Martin V. Chauvin, Chief, Carrier Safety Bureau, Department of Transportation, State Campus, 1220 Washington Avenue, Albany, NY 12232; Mr. Martin V. Chauvin Chief Carrier Safety Bureau Department of Transportation State Campus 1220 Washington Avenue Albany NY 12232; Dear Mr. Chauvin: This responds to your August 5, 1980, letter asking why it might not b possible for a manufacturer to certify a vehicle in compliance with the school bus safety standards if that vehicle transports 10 persons or less. You state that you would like the smaller sized vehicles to be constructed with the same safety features as larger school buses.; First, we would like to note that the school bus safety standards wer originally applied only to the larger sized vehicles (more than 10 persons) because the larger sized vehicles were not previously required to comply with many of our safety standards. On the other hand, most of our standards apply to vehicles transporting 10 persons or less. Since these small vehicles were extensively regulated it was determined to be unnecessary to apply school bus safety standards to them.; In response to your particular question, a vehicle transporting 1 persons or less is a multipurpose passenger vehicle (MPV), not a bus or a school bus. A manufacturer is required by this agency to certify such a vehicle in compliance with the safety standards applicable to multipurpose passenger vehicles. This certification statement must be made on the vehicle's certification label. Therefore, a manufacturer cannot certify a vehicle as a school bus in compliance with the school bus safety standards unless the vehicle is of a size that puts it within the school bus category (more than 10 persons).; New York should not attempt to issue a regulation that would requir multipurpose passenger vehicles to comply with all school bus safety standards. Some of those standards might conflict with other Federal safety standards applicable to MPV's and would, therefore, be preempted. For example, the school bus seating standard could not be applied to MPV's because their seating is regulated by other Federal safety standards. However, since MPV's are not presently regulated in the areas of emergency exits, joint strength, or roof crush, New York could have a regulation requiring MPV's used to transport children to comply with these performance standards now applicable only to school buses. The vehicles would still be required to be certified only to the safety standards applicable to MPV's, however.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0985OpenDr. Ing. E. Lange, Alfred Teves GmbH, Postfach 119 155, Frankfu- rt/M, Germany; Dr. Ing. E. Lange Alfred Teves GmbH Postfach 119 155 Frankfu- rt/M Germany; Dear Mr. Lange: Mr. Paul Utans asked us to provide you with an interpretation o paragraph S5.3.3 of Motor Vehicle Safety Standard No. 105a, *Hydraulic Brake Systems.* Mr. Utans asks for confirmation of his understanding; >>>'that the indicator lamp shall remain activated either without th application of any pedal force or with one application of a pedal force (with a range of 25 or 50 pounds, as the case may be) if a failure of the kind described in S5.3.1(a) to S5.3.1(c) exists in the service brake system.'; This interpretation is only partially correct. Paragraph S5.3.3 state in pertinent part:; '...each indicator lamp, once activated, shall remain activated as lon as the condition exists, whenever the ignition switch is in the on position. An indicator lamp activated when the ignition turned to the 'start' position shall be deactivated upon return of the switch to the 'on' ...position... unless a failure of the kind described in S5.3.1(a) to S5.3.1(c) exists in the service brake system.'<<<; Paragraph S5.3.1(a) allows a brake pressure failure to be initiall indicated either before or upon application of pedal force, but thereafter the light must remain activated while the ignition switch is in the 'on' position. However, if the failure is present when the vehicle is first started, the indicator lamp must immediately be activated before any application of pedal force, until the failure condition no longer exists.This interpretation is subject to modification by response to petitions for reconsideration of Standard No. 105a, scheduled for publication around May 1, 1973; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1697OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P. O. Box 898, Sacramento, CA, 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P. O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Your letters of November 6, 1974 and November 19, 1974 to Jim Brelan of Denver, Colorado (copies enclosed) have come to our attention and we have some comments to make on them.; The two letters in question concern the use of multiple front, middle and rear side marker lamps. Your letter of November 6 states that 'your intermediate side marker lamps at non-specified locations are not permitted and must be removed.' With respect to your letter of November 19, it is your view that an array of five side marker lamps 'installed at the top and bottom of each side' of a trailer over 30 feet in length is improper and that 'two of the top and two of the bottom ones on each side must be removed.' The single lamp remaining at the mid point and at each end of the vehicle 'shall be located at or near the front, center and rear on each side at the top and bottom or top or bottom.' You conclude that 'This requirement is not only a California regulation but is also in Federal Motor Vehicle Safety Standard No. 108.'; The letters are incorrect in several respects. First of all, Standar No. 108 does not prohibit the use of more than one side marker lamp, front, rear, or center, provided the additional lamps do not impair the effectiveness of any required lighting equipment. Secondly, such lamps may be mounted at any height on the trailer body 15 inches or more above the road surface. They need not be 'at the top and bottom or top or bottom.' To the extent that California laws prohibit multiple marker lamps or prescribe mounting of marker lamps other than as permitted by Standard No. 108, those laws are preempted by Section 103(d) of the National Traffic and Motor Vehicle Safety Act of 1966.; Yours truly, Richard B. Dyson, 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.