NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
Interpretations | Date |
---|---|
ID: nht73-1.30OpenDATE: 10/25/73 FROM: E. T. Driver; NHTSA TO: Marchal America TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter #8495, dated October 5, 1973 to the National Highway Traffic Safety Administration concerning the legality of an automotive headlamp having a sealed metal reflector, glass lens arrangement. It is understood from your letter that such a headlamp would meet all requirements of Federal Motor Vehicle Safety Standard No. 108, including photometric and electrical performance, interchangeability and mechanical aiming. Specifically your question is: "Would a hermetically sealed metal and glass headlamp, (one in every way interchangeable with existing approved sealed beams except that the reflector would be metal instead of glass), be acceptable under current federal regulations?" The answer to your question is "yes". |
|
ID: nht73-1.31OpenDATE: 12/04/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Young Daybrook, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 16, 1973 asking about the proper location of indentification lamps on one-man truck-tractor cabs that are offset from the vertical centerline of the vehicle. In your view "when the Law is applied to one (1) man cabs, the possibility exists that oncoming traffic would interpret the truck as not being in its proper traffic lane." As you have pointed out, front identification lamps are required by Table II of Standard No. 108 to be "as close as practicable to the tope of the vehicle . . . as close as practicable to the vertical centerline. . . ." The "vertical centerline" is that of the vehicle which is usually that of the cab as well. However, an identification lamp arrangement around the vertical centerline of an offset cab is considered to meet the standard. We are not aware that an actual safety problem is presented by the current practice of mounting identification lamps around the centerline of offset cabs, and the fact that you produce less than 1,000 vehicles per year does not relieve you of the requirement of providing these lamps. Yours truly, ATTACH. Young Daybrook Inc. November 16, 1973 U.S. DEPARTMENT OF TRANSPORTATION -- NATIONAL HIGHWAY SAFETY ADMINISTRATION Gentlemen: We request your assistance in interpreting FMVSS #108; Lamps etc., as applied to the vehicles we manufacture under the "OTTAWA" name and illustrated in the attached brochure #30-2500-4/73. These vehicles are all over 10,000# GVW; all over 80" in width; and all have one (1) man cabs, either 37" or 48" wide; located left of centerline of the vehicle. The Law requires all truck tractors to have three (3) amber identification lamps "As close as practicable to the verticle centerline". When the Law is applied to one (1) man cabs, the possibility exists that oncoming traffic could interpret the truck as not being in its proper traffic lane. Your earliest possible response would be appreciated and should it be pertinent, we produce fewer than 1000 trucks per year. Very truly yours, James H. Swinghammer -- Assistant Chief Engineer Attachment |
|
ID: nht73-1.32OpenDATE: 07/20/73 FROM: AUTHOR UNAVAILABLE; L. R. Schneider for J. E. Wilson; NHTSA TO: Oregon Traffic Safety Commission TITLE: FMVSS INTERPRETATION TEXT: Thank you for the copy of Oregon House Bill 2721 that you enclosed in your letter of June 25, 1973. We have reviewed it carefully, and have concluded that virtually all of Section 2 is preempted by 15 U.S.C. 1392(d) (copy enclosed). As you may know, this section of the National Traffic and Motor Vehicle Safety Act prohibits a State from having a safety standard applicable to the same aspect of performance as a Federal safety standard unless it is identical to the Federal standard. In this instance, the relevant Federal standard is 49 CFR @ 511.108 Standard No. 108, Lamps, reflective devices, and associated equipment. Section 2 of HB 2721 requires motor vehicles manufactured after October 1, 1975, to be equipped with a green-yellow-red rear mounted lighting system. The NHTSA considers Standard No. 108 to include within its scope all lighting equipment required to be used on the rear of motor vehicles to which it applies. Any State requirements that have the effect of regulating such equipment must therefore be identical to the relevant provision of Standard No. 108. Section 2 of HB 2721 is not identical to the Federal standard relating to that aspect of performance, and must therefore be considered as invalidated as that category of vehicle is expressly excluded from Standard No. 108. Portions of Section 3 (ORS 483.412(3)(a) and (b)) are invalidated for the same reason. The remainder of Section 3 and Section 4 does not conflict with the relevant provisions of Standard No. 108. The guiding principle that we have applied to this situation is that the State requirements that regulate the design of motor vehicles must be identical to the Federal standards. It was clearly the intent of Congress to provide for uniformity of regulation of the manufacturer in areas where the Federal agency has acted, and they did so by the identity requirements of section 1392(d). Sincerely, Enclosures OREGON TRAFFIC SAFETY COMMISSION June 25, 1973 James E. Wilson -- Associate Administrator for Traffic Safety Programs, U.S. Department of Transportation, National Highway Traffic Safety Administration Dear Mr. Wilson: The Oregon Legislature passed H.B. 2721 which allows a green, yellow and red taillight system. A copy is attached for your information. Sincerely, Gil W. Bellamy [Enclosure Omitted.] |
|
ID: nht73-1.33OpenDATE: 04/12/73 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Trailmobile TITLE: FMVSS INTERPRETATION TEXT: We have received copies of your letter of March 28, 1973, to the ten Regional Administrators of this agency, concerning the compliance of your vehicles with Standard No. 108. You state that law enforcement officials in certain jurisdictions are citing your semitrailers for lack of clearance lamps when, as a matter of fact, the vehicles are equipped with combination turn signal and clearance lamps located near the lower rear corners of the vehicle. You ask the Regional Administrators to advise the local authorities that this lamp configuration conforms to Standard No. 108 and "that any conflicting state regulation is unenforceable under the provisions of Section 103(d) of the Traffic Safety Act." Paragraph S4.3.1.4 of Standard No. 108 states, "Where the rear identification lamps are mounted at the extreme height of a vehicle, rear clearance lamps need not meet the requirement of Table II that they be located as close as practicable to the top of the vehicle." Since the identification lamps depicted in your drawing are at the extreme height of the vehicle, the location you have chosen for the clearance lamps in allowed by Standard No. 108. Section 103(d) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1392(d), renders void any State law with differing requirements for this equipment. I am sending a copy of this letter to the Regional Administrators. Sincerely, March 28, 1973 This letter was sent to Regional Administrator, Dept. of Transportation, National Highway Traffic Safety Administration, at each of the 10 Regional Offices on attached page. Dear Sir: In the past few months we have (upon customer specification) been building highway semi-trailers with only the three identification lamps on the top-rear of the vehicle. The two rear clearance lamps have been combined with the turn-signal lamps and are not at the customary top corner locations (SEE ATTACHED SKETCH). In our opinion this is a perfectly legal situation under sections S4.3.1.5 and S4.4.1 of Federal Motor Vehicle Safety Standard #108, established pursuant to Public Law 89-563. In some states, these vehicles are being cited for "not having rear clearance lamps", due in part I feel to a lack of knowledge or understanding on the part of the state enforcement people that these trailers in fact do have the legally required lamps. Would you please inform the proper enforcement people in the states within your region of the legality of this particular lamp configuration under Federal law and that any conflicting state regulation is unenforceable under the provisions of Section 103(d) of the National Traffic and Motor Vehicle Safety Act of 1966 (Public Law 89-563). Please advise the undersigned of the situation with respect to this matter in your particular region so that we may in turn inform our customers accordingly. Sincerely, R. J. Deller -- Vice President of Engineering, TRAILMOBILE c: J. E. Cook; E. Hammond; R. P. McArdla - Chicago; E. E. Lungren - Chicago; R. Dyson-D.O.T., Wash. D.C. w/sketch NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION REGIONAL ADMINISTRATORS Region I * Transportation Systems Center Connecticut, Maine, Massachusetts, 55 Broadway New Hampshire, Rhode Island, Vermont Cambridge, Massachusetts 02142 Region II 4 Normanskill Boulevard New York, New Jersey, Puerto Rico Delmar, New York 12050 518 472-4095 Region III Room 1633, Federal Building Delaware, District of Columbia, Maryland, 31 Hopkins Place Pennsylvania, Virginia, West Virginia Baltimore, Maryland 21201 301-962-3878 Region IV Suite 200, 1720 Peachtree Road, NW Alabama, Florida, Georgia, Kentucky, Atlanta, Georgia 30309 Mississippi, North Carolina, South 404-526-5537 Carolina, Tennessee Region V 18209 Dixie Highway Illinois, Indiana, Minnesota, Michigan, Homewood, Illinois 60430 Ohio, Wisconsin 312-799-6300 X-21 Region VI 819 Taylor Street Arkansas, Louisiana, New Mexico, Oklahoma, Fort Worth, Texas 76102 Texas 817-334-2021 Region VII P.O. Box 7186, Country Club Station Iowa, Kansas, Missouri, Nebraska Kansas City, Missouri 64113 816-361-0860 X-7887 Region VIII Room 242, Building 40 Colorado, Montana, North Dakota, Denver Federal Center South Dakota, Utah, Wyoming Denver, Colorado 80225 303-233-3611 X-6429 Region IX 450 Golden Gate Avenue Arizona, California, Hawaii, Nevada P.O. Box 36096 San Francisco, California 94102 415-556-5450 Region X Room 412, Mohawk Building Alaska, Idaho, Oregon, Washington 222 S.W. Morrison Street Portland, Oregon 97204 503-226-3361 X-1754 * Handled out of Delmar office until further notice. Truck Body & Equipment Association, Inc., DOT CHART-5 Supplement 3/31/71 TRAILER REAR LAMP LOCATIONS FOR COMPLIANCE WITH FMVSS #108 (Graphics omitted) |
|
ID: nht73-1.34OpenDATE: 06/13/73 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: The Grote Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: In your letter of June 4, 1973 you have asked whether a manufacturer may comply with revisions made by the SAE to SAE standards incorporated by reference in Standard No. 108 in the absence of an amendment by NHTSA. The answer is no, and your understanding is correct. A manufacturer must comply with the specific SAE standard and revision set forth in Standard No. 108, regardless of any succeeding revisions made by the SAE. Sincerely, June 4, 1973 U.S. Department of Transportation National Highway Traffic Safety Administration Attention Lawrence R. Schneider -- Chief Counsel Dear Mr. Schneider: The Grote Manufacturing Company is an independent manufacturer of vehicle lighting equipment. In addition to supplying replacement items, we also supply a large number of original equipment vehicle manufacturers. Recently, it has come to our attention that some vehicle manufacturers are under the impression that if an SAE Lighting Standard is referenced in Federal Motor Vehicle Safety Standard 108, they are then permitted to comply to that basic standard, even if the SAE adopts a revision to the standard. For the purpose of citing an example only, MVSS 108 currently requires that turn signal lamps comply with SAE J588d, June, 1966. A later standard, SAE J588e was adopted by the SAE in September of 1970. The specific point in question is whether or not a vehicle manufacturer has the option of complying with the later SAE standard, rather than the one specifically referenced in MVSS 108. A further example could be cited where sidemarker lamps are currently required to comply with SAE J592c. The SAE has again modified this standard and adopted J592d. Specifically, must the manufacturer comply with the referenced DOT standard or does he have the option of adopting the later revision which SAE has issued? It has always been our understanding that the referenced SAE standards apply not only to the basic standards, such as a stop lamp, but rather to the very specific standard including the suffix letter which are cited in MVSS 108. However, we want to be certain we are correct before passing this information on to those customers who have raised this question. Yours very truly, THE GROTE MANUFACTURING COMPANY -- Paul G. Scully, Vice President |
|
ID: nht73-1.35OpenDATE: 12/19/73 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Toyo Kogyo U.S.A. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 6 to Mr. Lewis Owen of this Office concerning the use of a special parking lamp bulb in one of your tail lamp assemblies. The location of the subject bulb in the lamp assembly, regardless of whether the switch is removed to make it inoperative, is permitted, providing that the other required lamps function as specified in Federal Motor Vehicle Safety Standard No. 108. Sincerely, TOYO KOGYO U.S.A. REPRESENTATIVE OFFICE December 6, 1973 Lewis Owen -- National Highway Traffic Safety Administration, U. S. Department of Transportation Dear Mr. Owen: This is in confirmation to our discussion on Nov. 27, 1973. On one of our models, we are now considering to utilize the parts for, between U. S. A. and Japan. In these rear combination lamps, there are No. 12 lamp, which is called with parking lamp which is different from FMVSS 108. Please find the attached sheet. The parking lamp is required in Japanese regulation, but not required in U. S. A. We are now thinking it will become irregular if it works. So we want to remove the switch from this lamp and it cannot work. But, for the U. S. A., we want the bulb to remain ( 3.4 W ) and end of coupler and cord. We must emphasize that there are no influences to another mechanism, ( Stop, tail, & backup lamp ). On the lamp housing, we want to put the caution. This parking lamp is only for Japan namely, "Japan 12 V, 3.4 W". We believe there is no mistake in user. Warmest regards, Gorou Utsunomiya -- Branch Manager, Detroit Branch cc; Dr. Sakashita, Mr. Niguma Enclosurer |
|
ID: nht73-1.36OpenDATE: 07/26/73 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Signal-Stat Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of July 10, 1973, to Mr. Schneider asking which SAE Standard incorporated into Standard No. 108 applies to turn signal operating units, SAE J589 or J589a. The correct standard is SAE J589. You noted that the tables in the standard refer to J589, while paragraph S5.1 states that subreferenced standards shall be those published in the 1970 edition of the SAE Handbook. The key word in S5.1 is "subreferenced", i.e., referred to only in an SAE standard itself referenced in the Federal standard. J589 is directly referenced, not subreferenced and the number identified is correct. An example of a subreferenced standard would be J575, which is mentioned in J589. Your truly, July 10, 1973 Office of Chief Counsel -- National Highway Traffic Safety Administration Attention: L. Schneider Gentlemen: We will appreciate in obtaining your interpretation relative to the testing regulations of the "Turn Signal" operating units. I. FMVSS#108, paragraph S.5.1 states: "S5. 1 SAE Standards and Recommended Practices subreferenced by the SAE Standards and Recommended Practices included in Tables I and III and paragraphs S4.1.4 and S4.5.1 are those published in the 1970 edition of the SAE Handbook". The 1970 SAE edition of SAE Standards contains SAE J-589a for Turn Signal operating units. II. On the other hand, Tables I & III of FMVSS #108 specifies SAE J-589 for Turn Signal operating units. Is it a conflict between paragraph S5.1 and the Tables I and III of FMVSS #108? Please inform which of the two mentioned SAE Standards is applicable for 1973, J-589a or J-589. Thank you for your cooperation. Very truly yours, SIGNAL-STAT CORPORATION -- Rene Politis, Director, Product Reliability and ASSURANCE DEPT. |
|
ID: nht73-1.37OpenDATE: 11/19/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Crane Carrier Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 7, 1973, to Mr. Schneider asking whether Standard No. 108 permits four identification lamps. It does not. The purpose of the three-lamp system is that vehicles 80 inches or more in overall width be clearly identified as large vehicles, and only the three-lamp system specified by the standard is permissible. Standard No. 108, however, allows some latitude in mounting. The system need not be mounted on the vertical centerline of the vehicle if the manufacturer determines that is impracticable. Since you appear to have made such a determination, the front identification lamp system should be placed "as close as practicable to the vertical centerline" with height and spacing requirements in accordance with Standard No. 108. Yours truly, NHTSA Office of Chief Counsel Attention: Larry Schnieder Dear Sir: In regards to trucks of 80 or more inches, are the three (3) lamps for front identification a minimum requirement? The front loader equipment requires a bumper guard across the center of the windshield over the cab which would obscure the center lamp. Would four (4) identification lamps be permissible, i.e., 2 on each side of the center? I would appreciate any advice or reference to a standard. Thanking you in advance. Very truly yours, Crane Carrier Company -- Darrell Gambill, Standards Engineer |
|
ID: nht73-1.38OpenDATE: NOVEMBER 23, 1973 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Mr. James C. Martin TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 9 to the U. S. Department of Transportation concerning the operation of 4-way flashers and brake lights on a 1972 Toyota. Since there is no requirement that the hazard warning signal (4-way flashers) be capable of operating independently of the stop signal, it is permissible for the stop signal to override the hazard warning signal. In fact, these signals on most passenger cars and multipurpose passenger vehicles manufactured in the United States operate similarly. |
|
ID: nht73-1.39OpenDATE: 06/19/73 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Bendix Automotive Aftermarket TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of May 30, 1973 and confirms the telephone conversation with Mr. Vinson of my staff on June 14, 1973. The amendments to Motor Vehicle Safety Standard No. 116 published on May 17, 1973 modified container labelling requirements only for silicone-based brake fluid and hydraulic system mineral oil (paragraph S5.2.2.3) and did not affect the requirements for conventional DOT 3 and DOT 4 fluids (paragraph S5.2.2.2) as you assumed. Therefore you appear to have no problem, and it is not necessary to consider your letter as a petition for reconsideration. Sincerely, Bendix Automotive Aftermarket May 30, 1973 Department of Transportation Attention: Lawrence R. Schneider, Chief Counsel Reference: Phone conversation with Mr. Taylor Vincent on 5/14/73 Dear Mr. Schneider: The revision to the FMVSS #116 Standard, as published May 17, 1973, has an effective date for label changes of July 1, 1973, but does not specifically authorize the sellers of Brake Fluid to exhaust existing container stock. The label changes are minor, as follows: Existing Safety Warnings: 1. FOLLOW VEHICLE MANUFACTURER'S RECOMMENDATIONS WHEN ADDING BRAKE FLUID. 2. KEEP BRAKE FLUID CLEAN AND DRY. Contamination with dirt, water, petroleum products or other materials may result in brake failure or costly repairs. 3. STORE BRAKE FLUID ONLY IN ITS ORIGINAL CONTAINER. KEEP CONTAINER CLEAN AND TIGHTLY CLOSED TO PREVENT ABSORPTION OF MOISTURE. 4. CAUTION: DO NOT REFILL CONTAINER, AND DO NOT USE FOR OTHER LIQUIDS. * New Safety Warnings: 1. FOLLOW VEHICLE MANUFACTURER'S RECOMMENDATIONS WHEN ADDING BRAKE FLUID. 2. KEEP BRAKE FLUID CLEAN. Contamination with dirt or other materials may result in brake failure or costly repairs. 3. CAUTION: STORE BRAKE FLUID ONLY IN ITS ORIGINAL CONTAINER. KEEP CONTAINER CLEAN AND TIGHTLY CLOSED. DO NOT REFILL CONTAINER OR USE OTHER LIQUIDS. * We have corrected the labeling as to the use of upper and lower case letters per the instructions of Mr. Taylor Vincent. The current safety warning label requirements are not inadequate for the conventional Brake Fluids. Bendix labeling for DOT 3 Brake Fluid conforms to the existing standard for safety warnings. This letter is a request for permission to exhaust container stock purchased prior to the July 1, 1973, effective date. Existing Bendix container stock is in the form of lithographed containers both filled and unfilled. A minimum of 60 - 90 days is required to modify lithography plates. If permission is not granted, this letter is to be considered a petition to amend the Docket No. 71-13, Notice 4, published May 17, 1973. Please amend this docket to give the conventional Brake Fluid sellers the right to exhaust stock purchased prior to the July 1, 1973, effective date. Very truly yours, Cam Brame -- Quality Assurance Analyst cc: M. J. Stepanek; B. Stubbs; R. Hasnerl; J. Howard |
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.