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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



Displaying 1181 - 1190 of 16510
Interpretations Date
 search results table

ID: aiam3162

Open
Mr. 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 responds to your October 9, 1979, letter relating to the prope classification of school buses on certification labels.; Your letter is accurate in that school buses may be designated a 'school buses' on their certification labels. The agency thinks that for the purpose of clarity the term 'school bus' should be included on the label to further clarify the particular design of the bus. All other buses that comply only with standards applicable to non-school buses must be certified as 'buses'.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam3498

Open
Mr. Ricky L. Newmayer, Mr. Jerry A. Corbett, Newbuilt Enterprises, 540 California Avenue, Sand City, CA 93955; Mr. Ricky L. Newmayer
Mr. Jerry A. Corbett
Newbuilt Enterprises
540 California Avenue
Sand City
CA 93955;

Dear Messrs. Newmayer and Corbett: This responds to your letter of May 26, 1981, regarding Safety Standar No. 205, *Glazing Materials*. Please accept my apologies for the lateness of our response. You request permission to install a 'Ballistic Cube 2000' in 500 motor vehicles over a two-year period for experimental purposes. The 'Ballistic Cube 2000' is a protective cubicle made of Lexgard that is installed inside a vehicle. Lexgard, a bullet-resistant material, does not comply with all the requirements of Standard No. 205. You urge us to grant your request on the basis that the data generated from such an experiment would be relevant to a rulemaking proceeding initiated by General Electric. (General Electric has petitioned NHTSA to amend Standard No. 205 to permit the use of protective bullet- resistant shields in vehicles. The agency granted this petition on November 28, 1980.); Standard No. 205 is an equipment standard which applies to all glazin materials used in passenger cars, buses, trucks, and multipurpose passenger vehicles. all automotive glazing materials, including those used in the Ballistic Cube 2000, must conform to the standard's requirements. Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act of 1966 (the Act) provides in part that no person shall sell or manufacture for sale any item of motor vehicle equipment that does not comply with any applicable Federal motor vehicle safety standard in effect on the date of the item's manufacture. Thus, if you were to manufacture for sale or sell a Ballistic Cube 2000 made of Lexgard or any other glazing material that does not comply with Standard No. 205, you would be in violation of section 108(a)(1)(A). (Section 108(b)(5) establishes that section 108(a)(1)(A) does not apply when the motor vehicle or item of motor vehicle equipment is intended solely for export and is so labeled.) Section 109 imposes a civil penalty up to $1,000 for each violation of Section 108.; We believe that installation of the Ballistic Cube 2000 in moto vehicles could possibly generate test data that could be valuable to the agency in the previously mentioned rulemaking proceeding. Unfortunately, however, NHTSA does not have the legal authority to grant you permission to make such an installation. NHTSA does not have statutory authority to exempt an equipment manufacturer from the requirements of Section 108(a)(1)(A) as it relates to motor vehicle equipment.; Section 123 of the Act authorizes the exemption of motor vehicles fro the safety standards. However, it does not authorize the exemption of motor vehicle equipment from equipment standards. As noted above, Standard No. 205 is an equipment standard applicable to glazing. Consequently, no exemption can be granted under section 123 that would excuse manufacturing, offering for sale or selling noncomplying glazing as part of the vehicles you wish to modify and sell, since you would also be considered an equipment manufacturer.; While the agency cannot grant you an exemption, it is pursuing th request made by G.E. regarding Lexgard. The agency anticipates issuing a notice of proposed rulemaking before the end of this year. If a final rule permitting the use of Lexgard were issued, you could commence manufacturing and installation of the Ballistic Cubes upon the effective date of that rule.; Even if that rule is issued, there may be other standards which must b considered. As we understand your materials, the installation of the Ballistic Cube 2000 in motor vehicles may affect the compliance of those vehicles with FMVSS No. 103, *Windshield Defrosting and Defogging Systems*, and FMVSS No. 201, *Occupant Protection in Interior Impact.* If you were to install a Ballistic Cube in a new vehicle, i.e., one that had not yet been purchased for purposes other than resale, you would violate section 108(a)(1)(A) if the vehicle no longer complied with one of those standards. Of course, since Standard Nos. 103 and 201 are vehicle standards, you could apply for an exemption from those standards. Section 108(a)(2)(A) of the Act would prohibit you from installing the Ballistic Cube in a used vehicle if such installation would destroy the vehicle's compliance with Standards 103 and 201.; The agency cannot definitively state whether installation of your cub in a motor vehicle would affect the compliance of the vehicle with Standards Nos. 201 or 103. NHTSA does not offer prior approval of compliance of any vehicle or equipment design with any safety standards before the manufacturer's certification of its product. It is the manufacturer's responsibility under the Act to determine whether its vehicle or equipment complies with all applicable safety standards and regulations and to certify its vehicle or equipment in accordance with that determination. The agency is willing to offer an opinion on whether a vehicle or motor vehicle equipment complies with a particular rule. Such an opinion is not binding on the agency or on the manufacturer. However, the information you have provided in your letter does not give us a sufficient basis on which to form an opinion. It would probably be difficult for the agency to offer an opinion concerning your compliance with Standard 203 regardless of the information you supplied, since that standard involves a dynamic performance test.; Apart from the requirements imposed by section 108(a)(1)(A) regardin compliance of safety standards, manufacturers of motor vehicle equipment also have general responsibilities under the Act regarding safety defects. Under sections 151 *et seq*., such manufacturers must notify purchasers about safety-related defects and remedy such defects free of charge. Section 109 imposes a civil penalty of up to $1,000 upon any person who fails to provide notification of or remedy for a defect in motor vehicle equipment.; I am sorry we are unable to accommodate you in this matter. However since it is beyond our legal authority to do so, we have no choice but to make the decision set forth in this letter. Please contact this office if you have any questions.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam2323

Open
Mr. Don Ellenberger, Volkswagen of America, 818 Sylvan Avenue, Englewood Cliffs, N.J. 07632; Mr. Don Ellenberger
Volkswagen of America
818 Sylvan Avenue
Englewood Cliffs
N.J. 07632;

Dear Mr. Ellenberger: I am writing to confirm your May 19, 1976, telephone conversation wit Mark Schwimmer of this office, concerning the effective dates of Federal Motor Vehicle Safety Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars.*; You were particularly concerned with one paragraph in the preamble o Notice 4 (41 FR 18659, May 6, 1976, Docket No. 71-19). That notice delayed the effective dates of certain requirements of the standard. The paragraph in question is:; >>>Manufacturers should note that, apart from the changed effectiv date for the requirement in S5.1.1 that vehicles be equipped with properly marked rims, there is no delay in the September 1, 1976, effective date of the standard's basic requirements, S5.1 (*Tire and Rim Selection*).<<<; Section S5.2, *Rim Marking*, is the only section of the standard tha applies directly to rims. Section S5.1 applies directly to vehicles. As Mr. Schwimmer explained, however, two aspects of S5.1 (both found in S5.1.1) involve rims as well.; The first sentence of S5.1.1 includes a 'suitability' requirement: >>>...each vehicle...shall be equipped with...rims that are listed b the manufacturer of the tires as suitable for use with those tires...<<<; The second sentence, as amended by Notice 4, reads: >>>On and after September 1, 1979, each such vehicle shall be equippe with rims that meet the requirements of this standard.<<<; The paragraph in question is simply a reminder that the 'suitability requirement, among others, is effective September 1, 1976, as originally established in Notice 3 (41 FR 3478, January 23, 1976).; Yours truly, Stephen P. Wood, Assistant Chief Counsel

ID: aiam3861

Open
Mr. John A. Russo, Mr. Jerome Ramsey, Legal Services of Eastern Missouri, Inc., P.O. Box 4999A, Field Station, 625 N. Euclid Avenue, St. Louis, MI (sic) 63108; Mr. John A. Russo
Mr. Jerome Ramsey
Legal Services of Eastern Missouri
Inc.
P.O. Box 4999A
Field Station
625 N. Euclid Avenue
St. Louis
MI (sic) 63108;

Dear Mr. Russo and Mr. Ramsey: This is in response to your letter of August 10, 1984, concernin Missouri's odometer disclosure requirements.; The Missouri disclosure form fails to meet federal disclosur requirements. If Missouri wants to use its Certificate of Title in lieu of the separate Federal form, it must refer to the Motor Vehicle Information and Cost Savings Act, 15 U.S.C. S 1981 *et seq*., state the date of the transfer and provide a space for the purchaser's signature. The National Highway Traffic Safety Administration (NHTSA) considers this signature to be essential. It is an acknowledgment that the purchaser was aware of the mileage and prevents the purchaser from later alleging the contrary.; In addition, the Missouri title certificate fails to meet th requirements of 49 C.F.R. S 580.4(c). While it does provide a space for the odometer mileage, it fails to state that the transferor certifies 'that to the best of his knowledge the odometer reading reflects the actual miles or kilometers the vehicle has been driven.' Furthermore, the form must provide alternate statements that the odometer reading reflects the mileage in excess of 99,999 miles or kilometers or that the mileage is not actual and should not be relied upon.; Please be advised that, to date, Missouri has not requested approva from NHTSA for use of its Certificate of Title as a substitute for the Federal form. If you have any additional questions, please do not hesitate to contact Judy Kaleta of my staff at (202) 426-2992.; Sincerely, Kathleen DeMeter, Assistant Chief Counsel for General Law

ID: aiam2773

Open
Janine M. Schulte, North Central Tank Repair, Box 300, Holdingford, MN 56340; Janine M. Schulte
North Central Tank Repair
Box 300
Holdingford
MN 56340;

Dear Ms. Schulte: This responds to your January 13, 1978, letter asking several question about a manufacturer's certification responsibilities under Part 568, *Vehicles Manufactured in Two or More Stages*.; In your letter, you enclosed a copy of a TBEA form and ask whether i complies with Federal regulations and where you can obtain copies. This form is supplied by TBEA to assist manufacturers in their own recordkeeping. It is not required by any Federal regulation. You should consult TBEA for copies of the form.; Secondly, you ask whether Standard No. 120, *Tire Selection and Rim for Motor Vehicles Other Than Passenger Cars*, has altered the responsibilities of the intermediate manufacturer. An intermediate manufacturer's responsibility for compliance with Standard No. 120 is the same as his responsibility for compliance with any other Federal motor vehicle safety standard.; In your third question, you ask whether the addition of a 'tag' o 'pusher' axle to a used chassis requires compliance with Standard No. 121, *Air Brake Systems*. The addition of one axle to a used chassis does not constitute the manufacture of a new chassis. Therefore, if the chassis were manufactured prior to the time that Standard No. 121 became effective, modification of the chassis would not need to comply with the standard. If the chassis already complies with the standard, you would be prohibited from rendering inoperative the compliance of the vehicle with the standard.; You ask what the penalties are for violation of the Federa certification requirements. Under the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1381 *et seq*.) violations of the Act or regulations are punishable by $1,000 per violation up to a maximum of $800,000 for a related series of violations.; In your last question you ask whether the incomplete vehicle documen should remain with the intermediate or final stage manufacturer on completion of a vehicle. The final stage manufacturer should retain the incomplete vehicle document.; Sincerely, Joseph J. Levin, Jr., Chief Counsel

ID: aiam2289

Open
Mr. Robert M. Brodkey, President, Intercraft Corporation, P.O. Box 4854, Washington, D.C. 20008; Mr. Robert M. Brodkey
President
Intercraft Corporation
P.O. Box 4854
Washington
D.C. 20008;

Dear Mr. Brodkey: This is in response to your March 29, 1976, letter concernin regulations applicable to farm tractor tires whose importation is contemplated by one of your clients.; Farm tractors are not 'motor vehicles' as that term is defined in th National traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1391 et Seq.). Accordingly, tires designed exclusively for use on farm tractors are not 'motor vehicle equipment.' Therefore, the importation of such tires and tubes is not subject to Federal motor vehicle safety standards or other regulations issued by the National Highway Traffic Safety Administration. We are unaware of any other regulations of the Department of Transportation concerning such tires.; Yours truly, Stephen P. Wood, Assistant Chief Counsel

ID: aiam5059

Open
Mr. Ray Wyatt 5207 N. 33rd St. Phoenix, AZ 85018; Mr. Ray Wyatt 5207 N. 33rd St. Phoenix
AZ 85018;

Dear Mr. Wyatt: This letter responds to your inquiry regarding th conversion of race cars into cars for use on the public roads. I apologize for the delay in this response. As I understand the question, based upon your letter and subsequent telephone conversations with David Elias of my staff, you intend to convert a race car designed for use solely on a race track into a vehicle that can be used on the public roads. I am pleased to have this opportunity to explain our regulations for you. NHTSA has authority to regulate the manufacture and sale of new motor vehicles and items of motor vehicle equipment. The National Traffic and Motor Vehicle Safety Act (the Safety Act) defines 'motor vehicle' as one 'manufactured primarily for use on the public streets, roads, and highways... .' 15 U.S.C. 1391(3). The Safety Act requires every manufacturer to certify that each of its new motor vehicles complies with all applicable safety standards (15 U.S.C. 1403) and prohibits any person from manufacturing, importing, or selling any new vehicle that does not comply with all applicable safety standards (15 U.S.C. 1397(a)(1)(A)). However, these requirements apply only until the first sale of the vehicle for purposes other than resale (15 U.S.C. 1397(b)(1)). After that first purchase, the Safety Act prohibits any manufacturer, distributor, dealer, or repair shop from 'rendering inoperative' any device or element of design installed in or on the vehicle in compliance with an applicable safety standard (15 U.S.C. 1397(a)(2)(A)). Manufacturers, distributors, dealers, and repair shops are thus free to modify vehicles after the first purchase of the vehicle. However, these entities are prohibited from performing any modification that would result in the vehicle no longer complying with the safety standards. In addition, unlike the situation with new vehicles, manufacturers, distributors, dealers, and repair shops that modify used motor vehicles are not required to certify that the vehicle complies with all applicable safety standards. Hence, if these race cars had ever been certified as motor vehicles complying with the safety standards, your conversions would be subject only to the 'render inoperative' prohibition of the Safety Act. Your situation appears to be different, however, in that you wish to place a race car, which had never been certified, on the public roads. Race cars are not 'motor vehicles' within the meaning of the Safety Act, so no party has ever certified that these vehicles meet the applicable safety standards. This means that the first introduction into interstate commerce or sale of these converted race cars as 'motor vehicles' for the purposes of the Safety Act would be by you after you perform the conversion. Accordingly, you would be legally responsible for certifying that the converted race cars comply with all applicable safety standards, in accordance with the regulations set forth in 49 CFR Part 567. As a manufacturer of a new motor vehicle under the provisions of the Safety Act, you would also be subject to the notification and remedy requirements of the Safety Act (15 U.S.C. 1411 et seq.) and 49 CFR Parts 573 and 577. This means that if either you or the agency determined that a non-compliance with a safety standard or safety related defect exists in your converted vehicles, you, as the manufacturer, would be required to notify purchasers of the determination and remedy the problem without charge to the purchaser. I have enclosed for your convenience an information sheet for new manufacturers that gives a brief overview of our laws and regulations and explains how to get copies of those regulations. You may also want to contact the State of Arizona to learn whether there are any state laws or regulations that would affect the conversion of a racing car to a passenger automobile, and its sale and registration in the state, as well as the insurance ramifications of such a conversion and sale. If you have any further questions or need any further information on this subject, please contact David Elias of my office at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosure;

ID: aiam2266

Open
Mr. 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 responds to Blue Bird Body Company's February 13, 1976, questio whether 47 described intersections of bus body components qualify as 'body panel joints' subject to the requirements of Standard No. 221, *School Bus Body Joint Strength*. You also ask what test procedures are used in testing joints if the means described in S6.1.1 or S6.1.2 cannot be employed due to the configurations of the intersecting components.; The terms which establish the applicability of the requirements of th standard to a particular section of a school bus body are defined in S4 of the standard. Read together, they establish the following test. If the edge of a surface component (made of homogeneous material) in a bus that encloses the bus' occupant space comes into contact or close proximity with any other body component, the requirements of S5 apply, unless the area in question is designed for ventilation or another functional purpose or is a door, window, or maintenance access panel. Applying this test to the 47 intersections of bus body components you describe, it appears that the areas corresponding to the following numbered paragraphs of your letter are bus body joints and therefore must meet the 60-percent joint strength requirements: 1, 4, 5, 6, 7, 8, 9, 11, 13, 14, 15, 19, 20, 23, 26, 28, 29, 50.; The front and rear headers described in paragraphs 2 and 12 ar considered primarily structural and have only an incidental role in enclosing the occupant space and, therefore, are not considered 'body panels' for purposes of the requirements.; The wire molding discussed in paragraphs 3 and 10 is considered maintenance access panel, excluded from the requirements only if a wire is installed behind the molding.; The bumper trim strip described in paragraph 17 is not considered t have a function in enclosing the occupant space and is therefore not considered a body component for purposes of the requirements.; Your assumption that components located entirely below the level of th floor line are not subject to the standard is correct. However, body panels that do 'enclose bus' occupant space' because a portion lies above the floor line are subject to the requirements. Thus, the rear center skirt described in paragraph 16, the bumper trim panel described in paragraph 18, and the auxiliary cross members described in paragraph 21 are not subject to the requirements.; The rubrails described in paragraphs 22, 23, 27, 28, and 29 are no themselves considered to have a function in enclosing the occupant space and therefore are not considered body components for purposes of the requirements. For purposes of testing the complex joints to which they are fastened, they should be modified as necessary to prevent them from affecting testing of the underlying joint.; The wheelhousing trim described in paragraph 24 is not considered t have a function in enclosing the occupant space and is therefore not considered a body component for purposes of the requirements.; Because the plywood described in paragraph 25 is attached to a floo panel and is only added to some buses for insulation purposes, it is not considered to have a function in enclosing the occupant space and is therefore not considered a body component for purposes of the requirements.; The extruded aluminum trim described in paragraph 30 is not considere to have a function in enclosing the occupant space and is therefore not considered a body component for purposes of the requirements.; The NHTSA agrees that paragraphs 30 through 36 and 38 through 4 describe joints between maintenance access panels and the bus body. The ventilation duct in paragraph 37 is the type of ventilation space that is not subject to requirements for joint strength.; In many of your requests for clarification, you asked what means woul be employed to test joints in which the two body components in question are not flat surfaces in the same or parallel planes. The NHTSA intends to test joints that are not capable of being tested as specified in S6.1.1 or S6.1.2 by determining the nature of the two body components and testing identical materials joined by the same means as is used by the school bus manufacturer. The materials will be flat and conform to the dimensions described in Figure 1, and they will be oriented in the same fashion as described in Figure 1. For example, the 90-degree angle at the joint described in paragraph 20 is ignored for purposes of the NHTSA test procedure by simulating the joint and using opposing forces in the same or parallel planes. In this way, the agency can examine a manufacturer's technique to see if the fastening method constitutes the exercise of due care in complying with the joint strength requirement.; You also asked what procedure would be used in testing joints wher more than two panels or body components are joined by one fastener (example in paragraph 29). In these cases, the definition of 'body panel joint' in S4 describes several joints, involving one at each intersection area that qualifies as joint. For each pair of components, the tensile strength of the weaker panel is determined, and the joint is required to sustain a load of not less than 60 percent of that tensile strength. For example, in the case of two side panels riveted to a bow, one joint would be between the two lapped panels and 60 percent of the weaker panel would be the test requirement. At the same time, a separate test of the joint between the bow and the panel that contacts the bow would be required, with 60 percent of the weaker component's tensile strength established as the level of strength for testing.; I trust that this discussion will permit a determination of wha portions of your products are subject to the requirements of Standard No. 221 and what test procedures are employed in satisfaction of the requirements.; Sincerely, Frank Berndt, Acting Chief Counsel

ID: aiam5409

Open
James H. Shuff, President Freedom Trailers P.O. Box 31, Brownfield Road Eaton, NH 03832; James H. Shuff
President Freedom Trailers P.O. Box 31
Brownfield Road Eaton
NH 03832;

"Dear Mr. Shuff: This responds to your letter asking whether tires an wheel rims used with your 'park model travel trailers' are subject to Federal Motor Vehicle Safety Standard (FMVSS) No. 120, Tire selection and rims for motor vehicles other than passenger cars. As explained below, the answer is no, because your travel trailers are not motor vehicles. Your letter provided the following information about your 'trailers.' The trailers are intended for recreational use, rather than for year round living. Each unit is a maximum of 400 sq. ft., and may be as wide as 12 feet. You state that after your trailers are constructed, they 'will be towed to their campsite and set up,' where they may be used for 'winter camping in the year round parks.' Once your trailers are set up, you would reuse the tires and rims. By way of background, 49 U.S.C. 30101 et seq. authorizes NHTSA to regulate new motor vehicles and motor vehicle equipment, including tires and rims. Standard No. 120, and all of our safety standards, apply only to vehicles that are 'motor vehicles,' within the meaning of the statute. The term 'motor vehicle' is defined at 49 U.S.C. 30102(a)(6) as: 'motor vehicle' means a vehicle driven or drawn by mechanical power and manufactured primarily for use on public streets, roads, and highways, but does not include a vehicle operated only on a rail line. We have determined that your 'trailers' are not motor vehicles based on two examinations. First, while the characteristics of your trailers are not entirely clear in your letter (our repeated attempts to reach you by telephone have been unsuccessful), it appears that your trailers could be considered 'mobile homes.' Mobile homes are regulated by the U.S. Department of Housing and Urban Development (HUD), and are not 'motor vehicles' subject to regulation by NHTSA. Accordingly, tire and rim selection for mobile homes is not subject to Standard No. 120 or any other NHTSA regulation. For information about mobile homes, you can contact the Assistant Secretary for Housing-Federal Housing Commissioner, U.S. Department of Housing and Urban Development, 451 7th St., SW, Washington, DC 20410. Second, even if your 'trailer' is not a mobile home, it does not meet the Safety Act definition of a 'motor vehicle.' We have interpreted the definition as follows. Vehicles designed and sold solely for off-road use are not considered motor vehicles, even though they may be operationally capable of highway travel. Vehicles, such as mobile construction equipment, that use the public roads only to travel between job sites and which typically spend extended periods of time at a single job site, are not considered motor vehicles. In such cases, the use of the public roads is incidental, not the primary purpose for which the vehicle was manufactured. On the other hand, if a vehicle is readily usable on the public roads and is in fact used on the public roads by a substantial number of owners, NHTSA has found the vehicle to be a motor vehicle. This finding was made with respect to dune buggies and regardless of the manufacturer's stated intent regarding the terrain on which the vehicles were to be operated. Based on your description, it appears that, analogous to mobile construction equipment, the on-road use of your travel trailers appears to be incidental and not the primary purpose for which they are manufactured. Therefore, your trailers are not subject to Standard No. 120's requirements for tire selection and rims. Please note that this conclusion is based solely on the facts presented in your letter. We may reexamine this conclusion if additional information becomes available that would warrant a reexamination. I hope that this information is helpful. If you have any questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel";

ID: aiam1919

Open
Mr. Sumner Meiselman, Truck Trailer Manufacturers Association, 2430 Pennsylvania Avenue, N.W., Washington, DC 20037; Mr. Sumner Meiselman
Truck Trailer Manufacturers Association
2430 Pennsylvania Avenue
N.W.
Washington
DC 20037;

Dear Mr. Meiselman: This responds to the Truck Trailer Manufacturers Association March 28 1975, request that the National Highway Traffic Safety Administration (NHTSA) review its position that building a trailer from new materials in combination with the running rear of an existing trailer constitutes the manufacture of a new vehicle subject to applicable safety standards. You also request confirmation that modification of the barrel of a tank trailer to replace compartments or to add to its volume does not constitute manufacture of a new vehicle.; NHTSA has already reconsidered its interpretation of what constitute the manufacture of a new truck in cases where components from an existing vehicle are used. Based on the high value of the drive train components found in powered vehicles, NHTSA has proposed an amendment of Part 571 that would supplant its earlier interpretation that, to constitute repair, the chassis of the existing vehicle must as a minimum be used in the new vehicle. The proposed amendment would establish that, in the assembly of a truck, a new vehicle is manufactured for purposes of compliance with and certification to applicable safety standards, unless the engine, transmission, and rear drive axles (as a minimum) of the rebuilt vehicle are not new, and at least two of these components were taken from an existing vehicle whose identity is continued in the rebuilt vehicle with respect to model year, vehicle identification number, and any other documentation incident to the vehicle's remanufacture and registration.; Our interpretation of what constitutes manufacture of a new traile (when use of components from an existing vehicle is involved) parallels our present interpretation of truck rebuilding in this area. We regret any confusion in our use of the term 'chassis', but we have made clear that the running gear and main frame of an existing vehicle, must, as a minimum, be used in the rebuilding of a vehicle to be considered a repair. I enclose copies of two letters which establish this point.; NHTSA does not view the manufacture of trucks and trailers a sufficiently similar to justify attempting to apply our newly-proposed position on truck rebuilding to trailer manufacture. The primary consideration of extremely high value of drive train components found in powered vehicles is not applicable to trailer manufacture. NHTSA also concludes that the economic considerations which discourage avoidance of Standard No. 121, *Air brake systems*, in truck manufacture do not operate in trailer manufacture.; In regard to tank trailer modifications where the tank serves th purpose of and replaces the frame rails, we would not consider replacement of compartments in the tank to be manufacture of a new vehicle. Similarly, the addition of volume in response to the new weight limits would not constitute manufacture of a new vehicle.; Sincerely, James C. Schultz, 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.