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: aiam0407OpenMr. Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Environmental Staff, General Motors Technical Center, Warren, MI, 48090; Mr. Louis C. Lundstrom Director Automotive Safety Engineering General Motors Environmental Staff General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in reply to your letter of July 12, 1971, to Mr. Douglas W Toms, Acting Administrator, concerning replacement equipment covered in FMVSS No. 108, effective January 1, 1972.; The requirements for original and replacement equipment in FMVSS No 108 cover those items listed in Tables I and III, namely:>>>; Headlamps, Tail lamps, Stop lamps, License plate lamps, Refle reflectors, Parking lamps, Side marker lamps, Backup lamps, Turn signal lamps,; Turn signal operating units, Turn signal flashers, Vehicular hazar warning signal operating units, Vehicular hazard warning signal flashers, Identification lamps, Clearance lamps, Intermediate side marker lamps, Intermediate reflex reflectors<<<; In addition the requirements cover the following items specified in th text of the standard:>>>; School bus warning lamps, Headlamp beam switching devices, Headlam upper beam indicator lamps, Turn signal pilot indicator lamps, Hazard warning signal pilot indicator lamps, Plastic lenses.<<<; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: nht87-2.21OpenTYPE: INTERPRETATION-NHTSA DATE: 06/23/87 FROM: DOUG COLE -- NATIONAL VAN CONVERSION ASSOCIATION INC TO: STEVE KRANTZKE -- NHTSA/ TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 11/01/88 FROM ERIKA Z JONES TO DOUG COLE; REDBOOK A32, STANDARD 302; LETTER DATED 06/29/87 FROM JONATHAN JACKSON TO DOUG COLE; LETTER DATED 06/22/87 FROM ROSE M TALISMAN TO DOUG COLE; LETTER DATED 06/08/87 FROM ROSE TAL ISMAN TO DOUG COLE TEXT: Hi Steve! It was a pleasure talking with you and thanks again for a speedy returned call. George Shiflett recommended I contact your office about an issue that has arisen from a Certification program that National Van Conversion Association (NVCA) sponsors. The i ssue surrounds the question of "compliance with FMVSS #302". A part of NVCA's Certification includes the physical gathering of random samples of fabrics, foams, carpets, and other flammable items that van conversion firms use in vehicles. These samples are then channeled to an accredited testing firm for destruct ive testing to verify compliance with FMVSS #302. NVCA has found many samples, according to the tests performed, not to be in compliance with FMVSS #302. The manufacturers of these samples vehemently oppose NVCA's findings and insist that their samples are indeed in compliance with FMVSS #302. In an effort to double check NVCA's test procedures, I contacted four major testing laboratories recommended by the American Association of Motor Vehicles Administrators. Half of those contacted suggested that NVCA's test methods were correct and the ot her half disagreed. Each half was quite certain they were right. The issue appears to be about when to use (or not to use) support wires in conjunction with the FMVSS #302 test. NVCA doesn't use any support wires in its test; some fabric manufacturers use support wires in their tests. In many (not all) instances, these support wires are an influence on whether a material passes or fails the FMVSS #302 test. Will you please clarify for us whether to use or not to use the support wires? I have enclosed copies of test procedures from NVCA's testing lab, a fabric manufacturer, Ford, and Fisher Body Division of GM for your review. Also enclosed is a copy of a letter NVCA will include with its communications with conversion firms (in the c ase of a FMVSS #302 failure, per NVCA's current test methods). If you see anything that we need to alter immediately, please contact me; if not, I realize your interpretations, comments, opinions, rulings, or whatever may take some time to formulate and NVCA will proceed as normal until we hear from you. Your assistance in this matter will be greatly appreciated by many involved. If I can provide any additional data or be of service in any way, please call on me. ENCLOSURE |
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ID: aiam2092OpenMr. Richard L. Kreutziger, Coach and Equipment Sales Corp., P.O. Box 36, Penn Yan, NY 14527; Mr. Richard L. Kreutziger Coach and Equipment Sales Corp. P.O. Box 36 Penn Yan NY 14527; Dear Mr. Kreutziger: This is in response to your letter of July 30, 1975, to Mr. Schwartz o this office, seeking an interpretation of Federal Motor Vehicle Safety Standard No. 205.; FMVSS No. 205 requires that the prime glazing manufacturer certify eac piece of glazing covered by the standard by marking it with the letters DOT, the manufacturers code mark assigned by the Department of Transportation and the markings required by section 6 of A.N.S.Z-26. The latter markings are the 'AS' number, the model number and the manufacturer's distinctive designation or trademark. The distributor who cuts a section of glazing material to which the standard applies is required to mark the material in accordance with section 6 of A.N.S.Z-26. Thus, each of the rectangular lites should be marked with the manufacturer's model number and trademark in addition to the AS number, but not with the letters DOT or the prime glazing manufacturer's DOT number.; Section 114 of the National Traffic and Motor Vehicle Safety Act o 1966 requires that you, as the vehicle manufacturer, certify that your product conforms to all applicable Federal motor vehicle safety standards. This would, of course, include FMVSS No. 205.; I hope I have fully answered your questions. If you have any furthe need for information please do not hesitate to write.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1411OpenMr. A. M. Fischer, Engineering Division, Mack Trucks, Inc., P. O. Box 1761, Allentown, PA, 18105; Mr. A. M. Fischer Engineering Division Mack Trucks Inc. P. O. Box 1761 Allentown PA 18105; Dear Mr. Fischer: This is in reply to your letter of February 4, 1974, concerning th location requirements of front identification lamps on certain solid-waste disposal vehicles.; You describe the vehicles in question as 'short BBC low cab-over-engin type vehicles -- equipped with a large volume body and a hydraulically operated front loader mechanism. This unit lifts containers of waste up and over the front of the cab and empties the waste into the top of the body. To prevent damage to the front of the vehicle and lamps, a protective guard is installed on the front centerline of the vehicle.' You further state that 'This guard could obstruct the center identification lamp.'; You ask whether or not all three of the front identification lamps ma be offset from the front centerline of the vehicle to ensure compliance with the visibility requirements of FMVSS No. 108. In accordance with paragraph S4.3.1, Table II of FMVSS No. 108 specifies that the front identification lamps be located 'as close as practicable to the top of the vehicle, at the same height, as close as practicable to the vertical centerline.' For the vehicles which you have described, it would appear that location of the front identification lamps either left or right of the vertical centerline would meet this requirement.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam0820OpenMr. Albert Hammerstein, Robert Bosch GmbH, Department K/BEW3, 7 Stuttgart 30, Postfach 400, Germany; Mr. Albert Hammerstein Robert Bosch GmbH Department K/BEW3 7 Stuttgart 30 Postfach 400 Germany; Dear Mr. Hammerstein: Your Broadview, Illinois, Subsidiary recently forwarded to us a copy o your December 17, 1971, letter concerning aiming adjustment tests as specified in SAE Standard J580a. A search of our files does not reveal that your letter was previously received by this Office.; Specifically, your concern is the interpretation of a requirement whic is specified in SAE J580a as follows:; >>>'2. The mechanism, including the aiming adjustment, must be s designed as to prevent the unit from receding into the lamp body or housing when an inward pressure of 50 lb(sic) is exerted on the outer surface of the lens.'<<<; Our interpretation of the above requirement is that no visible recedin of the sealed beam unit is permitted when the inward pressure is applied on the outer lens surface. Testing for compliance to the requirements of FMVSS No. 108, which references SAE J580a, is conducted on the basis of this interpretation.; In the upcoming Notice of Proposed Rule Making (NPRM) on FMVSS No. 10 (Docket 69-19), we are considering the feasibility of specifying more objective type requirements on this aspect of aiming adjustment tests for headlamps. You will no doubt be interested in commenting on the proposed requirements after issuance of the NPRM.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam5658OpenJane Thornton Mastrucci, Esq. Thornton, Mastrucci & Sinclair 4699 Ponce de Leon Boulevard Coral Gables, FL 33146-2188; Jane Thornton Mastrucci Esq. Thornton Mastrucci & Sinclair 4699 Ponce de Leon Boulevard Coral Gables FL 33146-2188; "Dear Ms. Mastrucci: This responds to your request for a interpretation as to which passenger vehicles and which multipurpose passenger vehicles (MPVs) meet the Federal Motor Vehicle Safety Standards (FMVSSs). You ask this since Florida law allows transportation of pupils in MPVs that meet 'all federal motor vehicle safety standards for passenger cars.' As explained below, in recent years many of the FMVSSs have been amended to have the same requirements for passenger cars and MPVs. However where differences exist, the only way your client, Dade County School Board, will be able to determine that a specific MPV meets the FMVSSs applicable to passenger cars would be to contact the vehicle's manufacturer. NHTSA is authorized under 49 U.S.C. Chapter 301 Motor Vehicle Safety to issue FMVSSs for new motor vehicles and new items of motor vehicle equipment. The FMVSSs are codified at Title 49 of the Code of Federal Regulations (CFR), Part 571. There are presently 53 FMVSSs. Each FMVSS's applicability section specifies the motor vehicles and/or equipment to which it applies. Under 49 U.S.C. section 30112, a person may not manufacture or sell any motor vehicle unless the vehicle meets all applicable FMVSSs and is so certified. Section 30115 establishes a self-certification system whereby the vehicle manufacturer is responsible for certifying that the vehicle meets the safety requirements in the standards applicable to the vehicle. In the certification, the manufacturer must specify the vehicle type (e.g., passenger car, MPV, truck, bus) of the vehicle. Each vehicle type's definition is found at 49 CFR Part 571.3 Definitions. Thus, a new passenger car sold in the U.S. must be certified by the manufacturer as meeting the FMVSSs applicable to passenger cars, and a new MPV must be certified as meeting the standards applicable to MPVs. In recent years, many FMVSSs have been amended to specify the same requirements for passenger cars and MPVs. For example, for model year 1998 vehicles, Standard No. 208, Occupant crash protection will specify identical requirements for passenger cars and MPVs. For Standard No. 214, Side impact protection, in July 1995, NHTSA issued a final rule in which MPVs manufactured after September 1, 1998 would be required to meet the same dynamic testing requirements as passenger cars. However, some safety standards that apply to both passenger cars and MPVs do not specify identical requirements for each vehicle type. For example, Standard No. 103 Windshield defrosting and defogging systems applies to passenger cars and MPVs, but specifies different requirements for each vehicle type. There is no easy way to determine whether a particular MPV meets the passenger car safety standards. Because of differences in FMVSS requirements for passenger cars and MPVs, for information whether a particular MPV meets the passenger car standards, you should contact the MPV's manufacturer. Please note that for some safety standards such as Standard No. 208, a manufacturer may have phased-in the compliance of its MPVs with the safety standard over several years. Therefore, some MPVs manufactured in a particular year may meet the newer standard but other MPVs may not. For information about whether a specific MPV meets the passenger car standards, the manufacturer should be provided with the MPV's seventeen digit vehicle identification number (VIN), which can be found on the vehicle's certification label on the hinge pillar, the door-latch post, or the door edge that meets the door-latch post, next to the driver's seating position. I hope this information is helpful. If you need any further information, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel"; |
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ID: aiam2948OpenMr. Leon Conner, P.O. Box 1671, San Angelo, TX 76902; Mr. Leon Conner P.O. Box 1671 San Angelo TX 76902; Dear Mr. Conner: We understand that a question has arisen concerning the testing o 'P-type' tires under the traction grading procedures of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104(f)(2)). Under the terms of the regulation, candidate tires are to be inflated to 24 psi prior to the traction test (49 CFR 575.104(f)(2)(i)(B) and (D), and (f)(2)(viii)), and are to be loaded to 85 percent of the load specified in Appendix A of FMVSS No. 109 (49 CFR 571.109), for the tires' size designation, at a cold inflation pressure of 24 psi (49 CFR 575.104(f)(2)(viii)). However, Appendix A lists cold inflation pressures for 'P-type' tires in kilopascals, with no stated inflation pressure corresponding precisely to 24 psi.; NHTSA chose 24 psi as the stated inflation pressure for UTQG tractio testing since it represents the recommended tire inflation pressure for most passenger cars. In the situation where no cold inflation pressure exactly equivalent to the specified pressure of 24 psi is stated in Appendix A of FMVSS No. 109 for a tire size designation, the tires to be tested are inflated to the pressure, listed for the tire size designation in Appendix A, which is nearest to 24 psi, *i.e.*, 180 kPa for tires with inflation pressures measured in kilopascals. The tires are then loaded to 85 percent of the load specified in Appendix A for the inflation pressure thus determined. The agency plans to issue an interpretive amendment to the regulation clarifying this point.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2553OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This is in reply to your letter of March 29, 1977, asking two question about the use of strobe lamps on school buses.; Your first question is whether it is 'legal to install strobe typ warning lamps on school buses?' The answer is yes provided such lamps meet the specific performance requirements in S4.1.4 which incorporates SAE Standard J887 'School Bus Red Signal Lamps.'; You also reference 'certification from our vendor. . . that his syste meets FMVSS if installed according to his instructions.' You have asked if this letter from your vendor is 'adequate documentation upon which we could certify that a bus with such a system meets FMVSS 108?' In an earlier opinion letter on this subject (to Yankee Metal Products Corporation of April 12, 1976) we opined opinion by a professional engineer indicating compliance of a strobe lamp design with SAE J887 provided a basis upon which Yankee could certify that its system meets Standard No. 108. Since you did not enclose the letter from your vendor we cannot comment upon it. However the National Traffic and Motor Vehicle Safety Act requires that a manufacturer exercise due care in insuring that its certification is not false and misleading in a material respect, and you should exercise the same care in this instance that you do with respect to insuring compliance of other items of lighting devices with which your buses are equipped.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam5330OpenMr. Derrick Barker John Martin Designs 1 Clifton St. Stourbridge, West Midlands DY8 3XR; Mr. Derrick Barker John Martin Designs 1 Clifton St. Stourbridge West Midlands DY8 3XR; Dear Mr. Barker: This responds to your letter concerning the buckl release requirement of Federal Motor Vehicle Safety Standard No. 213, 'Child Restraint Systems.' I apologize for the delay in responding. You asked for the 'tensile load requirements for the buckle and tongue.' There is no specific requirement in Standard 213 for the tensile force that a child restraint buckle must withstand. Instead, the buckle must maintain its integrity when the child restraint is subjected to a simulated frontal impact at 30 mph with either a six-month-old (17 pounds (lbs.)) or three-year-old (33 lbs.) sized dummy restrained in the car seat. At the conclusion of the simulated impact, the force required to depress the latch button to release the buckle is measured and must be 16 lbs. or less. You also asked for a copy of Procedure D of the American Society for Testing and Materials Standard D756-78. Section S5.4.2 of FMVSS No. 213 sets forth those requirements by making reference to section S4.3(b) of FMVSS No. 209. which, in turn, leads to the reference to Procedure D of ASTM D756-78. The material you requested is enclosed. In addition, you asked for a list of laboratories that test child safety seats and buckles. NHTSA does not endorse particular test laboratories. However, I can provide you with a list of laboratories we are aware of that conduct child restraint compliance tests. There may be other laboratories that can test child safety seats and buckles. Please contact Ms. Deirdre Fujita of my staff if you have further questions. Sincerely, John Womack Acting Chief Counsel Enclosures; |
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ID: aiam2949OpenMr. Leon Conner, P.O. Box 1671, San Angelo, TX 76902; Mr. Leon Conner P.O. Box 1671 San Angelo TX 76902; Dear Mr. Conner: We understand that a question has arisen concerning the testing o 'P-type' tires under the traction grading procedures of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104(f)(2)). Under the terms of the regulation, candidate tires are to be inflated to 24 psi prior to the traction test (49 CFR 575.104(f)(2)(i)(B) and (D), and (f)(2)(viii)), and are to be loaded to 85 percent of the load specified in Appendix A of FMVSS No. 109 (49 CFR 571.109), for the tires' size designation, at a cold inflation pressure of 24 psi (49 CFR 575.104(f)(2)(viii)). However, Appendix A lists cold inflation pressures for 'P-type' tires in kilopascals, with no stated inflation pressure corresponding precisely to 24 psi.; NHTSA chose 24 psi as the stated inflation pressure for UTQG tractio testing since it represents the recommended tire inflation pressure for most passenger cars. In the situation where no cold inflation pressure exactly equivalent to the specified pressure of 24 psi is stated in Appendix A of FMVSS No. 109 for a tire size designation, the tires to be tested are inflated to the pressure, listed for the tire size designation in Appendix A, which is nearest to 24 psi, *i.e.*, 180 kPa for tires with inflation pressures measured in kilopascals. The tires are then loaded to 85 percent of the load specified in Appendix A for the inflation pressure thus determined. The agency plans to issue an interpretive amendment to the regulation clarifying this point.; Sincerely, Joseph J. Levin, Jr., 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.