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: aiam0266OpenMr. B. Borisoff, Consulting Engineer, 5403 Blanco Avenue, Woodland Hills, CA 91364; Mr. B. Borisoff Consulting Engineer 5403 Blanco Avenue Woodland Hills CA 91364; Dear Mr. Borisoff: Reference is made to your letter of October 14, 1970 to Secretary Volp regarding our Consumer Information publication.; Concerning your comments on stopping distance, the wording used on pag 4 is the exact wording of this regulation. The category 'Stopping distance in feet with emergency brakes (partial service brake system)' is a generalization of the regulatory wording meant to convey the sense of this requirement to a consumer who may have no engineering background. The paragraph on page 193 paraphrases the regulatory wording. The title 'Partial Failure on One System' is, again, meant to convey the meaning to an otherwise uninformed consumer. I trust this clarifies the situation for you.; The reason many motorcycles are not listed is the fact that the dat was not received in time to be included in the book. I am enclosing copies of the data available for U.S. made motorcycles as you requested.; Volume 2, covering the 1971 makes and models will be availabl approximately November 15, 1970 and can be obtained from the Government Printing Office at a cost of $2.00. In addition two (2) new Consumer Aid publications entitled 'BRAKES - A Comparison of Braking Performance for 1971 Passenger Cars' and 'TIRES - A Comparison of Tire Reserve Load for 1971 Passenger Cars' will also be available at a cost of $.40 each.; Many thanks for your kind words and your interest in our motor vehicl safety program.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam2876OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, NY 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York NY 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d)(1)(iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard No. 109, other than a deep tread, winter-type snow tire or space- saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors corporation to revise the effective dates for Part 575.104(d)(1)(iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2877OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, NY 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York NY 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d)(1)(iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard No. 109, other than a deep tread, winter-type snow tire or space- saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors corporation to revise the effective dates for Part 575.104(d)(1)(iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2875OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, New York 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York New York 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d) (1) (iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard no.l 109, other than a deep tread, winter-type snow tire or space-saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors Corporation to revise the effective dates for Part 575.105(d) (1) (iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2454OpenMr. Rex R. Redhair, Shughart, Thomson and Kilroy, 922 Walnut Street, P. O. Box 13007, (sic); Mr. Rex R. Redhair Shughart Thomson and Kilroy 922 Walnut Street P. O. Box 13007 (sic); Dear Mr. Redhair: Your October 20, 1976, letter to the U.S. Department of Transportation Federal Highway Administration, has been referred to this office for reply.; You request data concerning the 10.00-02 'Inland Deep Drive 300,' tha was manufactured by the Mansfield Tire and Rubber Company, Mansfield, OH. Tire Identification Number WLZJAVN 503.; We have enclosed all the Federal Motor Vehicle Safety Standards for: >>>o New Pneumatic Tires, Passenger Cars, Federal Motor Vehicle Safet Standard No. 109; o New Pneumatic Tires for Vehicles Other Than Passenger Cars, Federa Motor Vehicle Safety Standard No. 119; o Part 574 - Tire Identification and Recordkeeping o Tire Code Numbers Assigned New Tire Manufacturers. o Tire Size Codes<<< The tire identification number stated in your letter can be explaine by the use of the above data.; >>>'WL' - is the plant code for the Mansfield, Ohio plant. 'ZJ' - is the tire size code for the 10.00-20 tire size designation. 'AVN' - is an internal code for Mansfield. '503' - means the tire was cured the 50th week of 1973.<<< You also request design and construction information. We do not hav this type of information because it is proprietary. Also enclosed are copies of tire 'Care and Service of Bias and Radial Ply Truck Tires.'; We hope the above has been of some help to you. Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Programs; |
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ID: 2908yyOpen Mr. David E. McAllister Dear Mr. McAllister: This responds to your letter of March 14, l99l, "as a supplier to the U.S. Postal Service for lights", asking whether it is "legal" for the center high mounted stop lamp to flash. We understand that the new postal service vehicles are trucks. Under Federal Motor Vehicle Safety Standard No. 108, the center highmounted stop lamp is required only on passenger cars. When installed as original equipment on a passenger car, it is required to be steady-burning when the brake pedal is applied. However, since Standard No. 108 does not require center highmounted stop lamps on motor vehicles other than passenger cars, any such lamps would not be required to be steady-burning. Thus, the current requirements of Standard No. 108 would permit a center lamp on a postal truck to flash. Supplementary lighting equipment, i.e., lighting equipment that is not required by Standard No. 108, is subject to Standard No. 108's general prohibition that such not impair the effectiveness of the lighting equipment required by the standard. The determination of impairment is to be made by the manufacturer of the vehicle before it certifies compliance with all applicable Federal motor vehicle safety standards. If it appears to be clearly erroneous, NHTSA will review the determination. With respect to the present case, it is theoretically possible that a flashing center stop lamp could "impair the effectiveness" of the truck's two steady-burning primary stop lamps by sending a confusing signal. However, given the lamp's location on the vertical centerline of the vehicle, and the public recognition of the function of the center lamp on passenger cars, we do not believe it is likely that the public would be confused. We would like to advise you that the agency has proposed that trucks be equipped with steady-burning center lamps, and that it has announced that a final rule will be issued during the first half of 1991. If the final rule applies to postal trucks, then a flashing center lamp could not be installed on postal trucks manufactured on and after the rule's effective date. Sincerely,
Paul Jackson Rice Chief Counsel Ref. l08 d:4/3/9l |
2009 |
ID: nht91-3.9OpenDATE: April 3, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: David E. McAllister -- Manufacturers Representative TITLE: None ATTACHMT: Attached to letter dated 3-14-91 from David E. McAllister to Paul Jackson Rice (OCC 5833) TEXT: This responds to your letter of March 14, 1991, "as a supplier to the U.S. Postal Service for lights", asking whether it is "legal" for the center high mounted stop lamp to flash. We understand that the new postal service vehicles are trucks. Under Federal Motor Vehicle Safety Standard No. 108, the center highmounted stop lamp is required only on passenger cars. When installed as original equipment on a passenger car, it is required to be steady-burning when the brake pedal is applied. However, since Standard No. 108 does not require center highmounted stop lamps on motor vehicles other than passenger cars, any such lamps would not be required to be steady-burning. Thus, the current requirements of Standard No. 108 would permit a center lamp on a postal truck to flash. Supplementary lighting equipment, i.e., lighting equipment that is not required by Standard No. 108, is subject to Standard No. 108's general prohibition that such not impair the effectiveness of the lighting equipment required by the standard. The determination of impairment is to be made by the manufacturer of the vehicle before it certifies compliance with all applicable Federal motor vehicle safety standards. If it appears to be clearly erroneous, NHTSA will review the determination. With respect to the present case, it is theoretically possible that a flashing center stop lamp could "impair the effectiveness" of the truck's two steady-burning primary stop lamps by sending a confusing signal. However, given the lamp's location on the vertical centerline of the vehicle, and the public recognition of the function of the center lamp on passenger cars, we do not believe it is likely that the public would be confused. We would like to advise you that the agency has proposed that trucks be equipped with steady-burning center lamps, and that it has announced that a final rule will be issued during the first half of 1991. If the final rule applies to postal trucks, then a flashing center lamp could not be installed on postal trucks manufactured on and after the rule's effective date. |
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ID: aiam3791OpenMr. A. Chambord, Standards Attache, The French Embassy, Suite 715, 2000 L Street, N.W., Washington, DC 20036; Mr. A. Chambord Standards Attache The French Embassy Suite 715 2000 L Street N.W. Washington DC 20036; Dear Mr. Chambord: This responds to your recent letter to Mr. Steve Kratzke of my staff asking for information on requirements applicable to tire rims for vans. The three points set forth in your letter are correct statements of the requirements, but I will reiterate them to be certain that you provide accurate information.; (1) Vans are considered 'motor vehicles other than passenger cars' fo the purposes of Federal Motor Vehicle Safety Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars* (49 CFR S571.120), and Standard No. 120 sets forth requirements which must be met by all new rims for use on vans. No other standard contains requirements applicable to those rims.; (2) Section S5.2(c) of Standard No. 120 requires the rim manufacture to permanently label each of its van rims with the letters 'DOT' as a certification that the rim satisfies the requirements of Standard No. 120. The manufacturer is expected to exercise due care before making such a certification. No outside inspector, either governmental or privately employed, need be consulted by a manufacturer before certifying the compliance of its rims.; (3) Rims entering into the United States are not individuall inspected, provided that the package containing the rims or the van on which the rims are installed bears an appropriate certification label. The only inspections at the port of entry are checks to see that a certification label is attached to the package of rims or the van.; Should you need any further information on this subject, please do no hesitate to contact me.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3384OpenMr. Charlton C. Davis, Davis Trailer Mfg. Co., Rte 1, Highway 78E, Loganville, Georgia 30249; Mr. Charlton C. Davis Davis Trailer Mfg. Co. Rte 1 Highway 78E Loganville Georgia 30249; Dear Mr. Davis: This responds to your November &, 1980, letter to Mr. Kratzke of m staff, in which you requested information concerning the legality of using welded mobile home axles and mobile home tires on trailers.; We have no regulations concerning the axles which may be used o trailers. However, the use if mobile home tires on new trailers would violate Federal Motor Vehicle Safety Standard No. 120 (49 CFR S571.120). For your information, I have enclosed a copy of this standard. Section S5.1 of the standard requires all new trailers equipped with tires for highway service to use tires that comply with either Standard No. 119, *New Pneumatic Tires for Use on Motor Vehicles Other Than Passenger Cars*, or Standard No. 109, *New Pneumatic Tires--Passenger Cars*, tires which have the label 'For Mobile Home Use Only' have been expressly exempted from the performance requirements of Standard No. 119. Because of the exemption, these tires may only be used on mobile homes. Therefore, the use of these tires on new trailers would render the trailers in violation of Standard No. 120. A manufacturer using these tires on a new trailer would face a fine of up to $1,000 for each mobile home tire used, pursuant to the provision of section 108 and 109 of the national Traffic and Motor Vehicle Safety Act as amended (15 U.S.C. 1397 and 11398). If you are aware of any such violations, the agency would appreciate any information you could supply.; As I Have stated above, we have no regulations specifying performanc requirements for the axles on trailers. If you have any further questions or need any further information on this subject, please contact Mr. Kratzke at (202) 426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4197OpenMr. Davis Thekkanath, Oshkosh Truck Corporation, P.O. Box 2566, 2307 Oregon St., Oshkosh, WI 54903-2566; Mr. Davis Thekkanath Oshkosh Truck Corporation P.O. Box 2566 2307 Oregon St. Oshkosh WI 54903-2566; Dear Mr. Thekkanath: This responds to your letter dated May 9, 1986, regarding the placemen of the vehicle identification number (VIN) on heavy duty vehicles. You asked whether a heavy duty truck must have a VIN that meets the location requirement of S4.6 of the standard or whether the VIN for such a vehicle can be located on the vehicle certification plate. As discussed below, the VIN for a truck with a gross vehicle weight ratings (sic) (GVWR) of 10,000 pounds or more can be located on the vehicle certification plate.; Standard No. 115, *Vehicle Identification Number - Basic Requirements* requires passenger cars, multipurpose passenger vehicles, trucks, buses, trailers, incomplete vehicles, and motorcycles to have a VIN. S4.5 of the standard requires the VIN to appear indelibly on a part of the vehicle which is not designed to be removed except for repair or upon a separate plate which is permanently affixed to the vehicle. S4.6 of the standard specifies the location of the VIN inside the passenger compartment for passenger cars, multipurpose passenger vehicles, and trucks of 10,000 pounds or less GVWR. However, the VIN location requirement of S4.6 does not apply to vehicles with a GVWR over 10,000 pounds.; As you correctly noted, Part 567, *Certification*, requires the VIN t be located on the certification label of motor vehicles. Since S567.4(b) requires the certification label to be permanently affixed to the vehicle, the agency considers providing the VIN in this location as complying with the requirement of S4.5 of Standard No. 115.; I hope this information is helpful to you. Sincerely, Erika Z. Jones, 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.