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: 3043yyOpen Ms. Debby Funk Dear Ms. Funk: This responds to your letter of June 4, l99l, to the Department requesting information regarding regulations on the display of lighted signs in vehicles. If they are not prohibited, you are interested in regulations governing size, placement, color, luminosity, and power source "(i.e. batteries, wire connections to either brake lights or cigarette lighter)." There are no Federal regulations or restrictions that directly prohibit the use of lighted signs in vehicles. However, there may be State and local laws that do. We are not in a position to advise you as to these laws, but you may write the American Association of Motor Vehicle Administrators for an opinion. The address is 4600 Wilson Boulevard, Arlington, Va. 22203. If you are contemplating a commercial venture in supplying lighted signs for use in motor vehicles, there are somewhat different considerations. Under the National Traffic and Motor Vehicle Safety Act, once a vehicle has been sold and in use, a manufacturer, distributor, dealer, or motor vehicle repair business may not modify it in any way that would create a noncompliance with any Federal motor vehicle safety standard with which the vehicle originally complied. Thus, installation of a lighted sign by any of the foregoing persons could affect compliance with Standard No. 111, Rearview Mirrors and Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. If the size of the sign interferes with the field of view in the interior mirror, a mirror must be provided on the exterior of the passenger side (most new cars today come equipped with these mirrors). If the sign is wired to the stop lamps, it must not result in a diminution of power that reduces the light from the lamp below the minimum levels specified in the standard. However, if the device is intended for owner installation, the foregoing discussion does not apply, as the Vehicle Safety Act does not prohibit owners from modifying their vehicles in any manner they choose, even if the modification creates a noncompliance. Our regulations do prohibit combining the center highmounted stop lamp with any other lamp or device such as a lighted display sign. However, there is no Federal prohibition governing manufacture and sale of these devices. If you have further questions, we shall be pleased to respond. Sincerely,
Paul Jackson Rice Chief Counsel ref:l08 d:6/25/9l |
2009 |
ID: nht91-4.29OpenDATE: June 25, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Debby Funk TITLE: None ATTACHMT: Attached to letter dated 6-4-91 from Debby Funk to The United States Department of Transportation (OCC 6130) TEXT: This responds to your letter of June 4, 1991, to the Department requesting information regarding regulations on the display of lighted signs in vehicles. If they are not prohibited, you are interested in regulations governing size, placement, color, luminosity, and power source "(i.e. batteries, wire connections to either brake lights or cigarette lighter)." There are no Federal regulations or restrictions that directly prohibit the use of lighted signs in vehicles. However, there may be State and local laws that do. We are not in a position to advise you as to these laws, but you may write the American Association of Motor Vehicle Administrators for an opinion. The address is 4600 Wilson Boulevard, Arlington, Va. 22203. If you are contemplating a commercial venture in supplying lighted signs for use in motor vehicles, there are somewhat different considerations. Under the National Traffic and Motor Vehicle Safety Act, once a vehicle has been sold and in use, a manufacturer, distributor, dealer, or motor vehicle repair business may not modify it in any way that would create a noncompliance with any Federal motor vehicle safety standard with which the vehicle originally complied. Thus, installation of a lighted sign by any of the foregoing persons could affect compliance with Standard No. 111, Rearview Mirrors and Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. If the size of the sign interferes with the field of view in the interior mirror, a mirror must be provided on the exterior of the passenger side (most new cars today come equipped with these mirrors). If the sign is wired to the stop lamps, it must not result in a diminution of power that reduces the light from the lamp below the minimum levels specified in the standard. However, if the device is intended for owner installation, the foregoing discussion does not apply, as the Vehicle Safety Act does not prohibit owners from modifying their vehicles in any manner they choose, even if the modification creates a noncompliance. Our regulations do prohibit combining the center highmounted stop lamp with any other lamp or device such as a lighted display sign. However, there is no Federal prohibition governing manufacture and sale of these devices. If you have further questions, we shall be pleased to respond. |
|
ID: nht80-1.35OpenDATE: 03/18/80 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Bertolini Engineering Co., Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of February 22, 1980, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. You have referenced our letter of May 5, 1977, to Mr. Dennis Moore of Dry Launch. That letter interpreted S4.3.1.1.1 with respect to a rear clearance lamp which indicated overall width though it was not located on the rear of the trailer. In that position it was not required to be visible at 45 degrees inboard. You have asked whether the same inboard visibility requirements may be eliminated for front clearance lamps "for the same reasons". The answer is yes. If a front clearance lamp that indicates overall width is not located at the front of the trailer, S4.3.1.1.1 relieves it of the requirement that it be visible at 45 degrees inboard. I hope this answers your question. SINCERELY, BERTOLINI ENGINEERING CO., INC. February 22, 1980 Frank Berndt Acting Chief Counsel U.S. Department of Transportation National Highway Traffic Safety Administration Dear Mr. Berndt: I am in receipt of a letter written to you on April 7, 1977 concerning the elimination of the requirement for inboard visibility of a rear clearance lamp for a truck trailer, and your reply of May 5, 1977 advising that the inboard visibility is not required. My question is as follows: Can the same inboard visibility requirement for the front clearance light of a truck trailer be eliminated for the same reasons as cited in your letter of May 5, applying the diagram shown in the April 7, 1977 letter, with the exception that the diagram applies to the front of a trailer instead of the rear. William A. Bertolini President |
|
ID: nht91-3.25OpenDATE: April 19, 1991 FROM: Andreas Geis -- Robert Bosch GMBH, Automotive Division TO: U.S. Department of Transportation, NHTSA TITLE: Re FMVSS 104, Windshield Wiping and Washing Systems, Effective: January 1, 1969. Loading State for developing (VISION) AREAS A,B,C. ATTACHMT: Attached to letter dated 6-18-91 from Paul Jackson Rice to Andreas Geis (A38; Std. 104); Also attached to letter dated 10-2-90 from Paul Jackson Rice to S. Kadoya TEXT: being a manufacturer of windshield wiper systems we are often required to develope the (Vision) Areas A,B,C as defined in FMVSS 104 S4.1.2.1 in conjunction with SAE Recommended Practice J903a, May 1966. We know from developing other vision areas and it has been recognized by the SAE (see SAE J903c, Nov 1973, para. 3.1.1) that the loading state of the vehicle is not without influence on the position and size of the Vision Areas. Unfortunately neither FMVSS 104 nor the older SAE J903a, which FMVSS 104 refers to, make any mention of the loading state. May we kindly ask you to inform us how this problem is normally handled? Is there perhaps a newer edition of FMVSS 104 or a preamble or a comment on this subject? Or is it left to the discretion of the manufacturer on which loading state he bases the development of the Vision Areas? We would greatly appreciate your early reply. |
|
ID: nht93-3.28OpenDATE: April 28, 1993 FROM: Frank Millar TO: John Womack -- Chief Council, NHTSA TITLE: None ATTACHMT: Attached to letter dated 9/1/93 from John Womack to Frank Millar (A41; Std. 105) TEXT: I have posed the following questions to Mr. Duane Perrin of NHTSA and he has been kind enough to give me answers over the telephone. Since I would like to get the answers in writing, Mr. Perrin has suggested I contact your office. 1. Would you please, for the record, document the spelling of your name, your phone number, fax number, and your position at NHTSA? 2. What is the significance, if any, of SAE J201, "In service Brake Performance Test Procedure, Passenger-Car and Light Duty Truck", subtitled SAE Recommended Practice Reaffirmed May 1989", to manufacturers and consumers? 3. What is the significance, if any, of the NHTSA's standard S571.105 to manufacturers and consumers? 4. As I read in the NHTSA standard S571.105, Paragraph S5.2.1 says that the parking brake of a Toyota Camry with a standard (stick shift) transmission must hold the car stationary on a hill with a 30% grade in both forward and reverse directions for 5 minutes. Is my interpretation correct?
Affidavit To the best of my knowledge, all of the answers to the above questions on all 3 pages are true and correct. Signature: Date: Printed Name: Signature Witness: Date Witness name: Please initial each page and fax your answers as well as return the originals by mail. If this is impractical in any way, please let me know. I appreciate your time spent answering these questions. Thank you very much. |
|
ID: 20944.drnOpenMonsieur Jean-Yves Le Bouthillier Dear Monsieur Le Bouthillier: This responds to your request for an interpretation of whether, in describing tests for school bus emergency exit doors, Standard No. 217, Bus emergency exits and window retention and release, specifies use of a parallelepiped 45 inches high, 22 inches wide and 6 inches deep for school buses that are 10,000 pounds or less gross vehicle weight rating (GVWR) and for school buses that are 12,000 pounds GVWR. As explained below, a parallelepiped of that size is specified for testing the first type of school buses and not the second type. Standard No. 217 specifies at S5.4.2.2, School buses with a GVWR of 10,000 pounds or less, that a school bus with a GVWR of 10,000 pounds or less "shall conform to all provisions of S5.4.2, except that the parallelepiped dimension for the opening of the rear emergency door or doors shall be 45 inches high, 22 inches wide, and six inches deep." Thus, a school bus with a GVWR of 10,000 pounds or less must have a rear emergency door or doors permitting unobstructed passage of a parallelepiped that is 45 inches by 22 inches by 6 inches. Since it is "more than 10,000 pounds," a school bus with a GVWR of 12,000 pounds would be subject to S5.4.2.1 School buses with a GVWR of more than 10,000 pounds:
In English measurements, the parallelepiped specified in S5.4.2.1(a)(1) is approximately 45 inches high by 24 inches wide by 12 inches deep. Thus, the parallelepiped specified for use in testing school buses of 12,000 pounds GVWR is wider and deeper than that specified for use in testing school buses with a GVWR of 10,000 pounds or less. I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, |
2000 |
ID: nht91-7.28OpenDATE: December 3, 1991 FROM: Michael H. Dunn -- Vice President, Marketing, Micho Industries TO: Paul Jackson Rice - Chief Counsel, U.S. Department of Transportation, NHTSA COPYEE: M. Hecker; C. Miller; J. Amabile; R. Rogers TITLE: Re: R-Bar Occupant Restraint System TEXT: Thank you for your letter of November 29, 1991, advising us of apparent mis-representations, relative to NHTSA's position with respect to the R-Bar (in two newspaper articles), and I wish to assure you that it was not our intent and that corrective action will be taken immediately within our sales organization. We understand that the NHTSA DOES NOT PROVIDE APPROVALS OF MOTOR VEHICLE EQUIPMENT and will advise our personnel to immediately refrain from using any such connotations. Again, we appreciate your comments and for bringing this matter to our attention. |
|
ID: nht69-2.22OpenDATE: 10/03/69 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: Donald J. Norris TITLE: FMVSS INTERPRETATION TEXT: This reply is in reference to your letter to Mrs. Knauer concerning Federal tire codes and tire tests, and a minimum service guarantee on tires. The list of tire manufacturer's approved code marks is periodically updated wherever new number are requereted or other chop as are necessary. The latest revision, a copy of which is enclosed, was printed on July 2, 1969. in the Federal Register. The tire code mumber, you realise, is placed on the tire to enable the consumer to identify the actual manufacturer of a tire. With respect to the minimum performance standards for passenger care times it is our intent to revise there standard and up-grade as necessary to protect the motoring public. It has been the policy of the National Highway Safety Bureau to retest tires when individual failures are found and to request the manufacturer of these tires to provide information concerning their basis of certifying compliance with Federal Motor Vehicle Safety Standard No. 109. When upon retesting a significant number of tires of a certain brand and line of tires are found to be defective, indicating that failures are not of the "isolated-instance type", this information has been released to the public and recall campains have been initiated. The Bureau has taken the position that an isolated instance of failure is not necessarily representative of the tires being manufactured and further verification is needed by retesting. We feel that the release of information on isolated failures would be confusing and serve no useful purpose to the consumer. The National Highway Safety Bureau has the responsibility of establishing safety standards for motor vehicles to reduce accidents.(Illegible Words) injuries in(Illegible Word) accidents.(Illegible Words) into relationships between the consumer and the caller of tires in cases involving(Illegible Word) service(Illegible Word). |
|
ID: nht93-8.9OpenDATE: November 12, 1993 FROM: J. Z. Peepas -- Selecto-Flash, Inc. TO: Taylor Vinson TITLE: FAX#202-366-3820 ATTACHMT: Attached to letter dated 11/30/93 from John Womack to J. Z. Peepas (A41; Std. 108) TEXT: ATTACHED ARE 4 PRINTS, A-1, A-2, B-1, B-2 WHICH COVER THE FOLLING: A-1 (40' CHASSIS) SHOWS 20' REFLECTIVE BEHIND THE GOOSE NECK FOR 40' CHASSIS WITH ONLY 6" PIECE WHITE REFLECTIVE MARKED ITEM 10, DELINEATING THE FRONT OF THE CHASSIS. THIS WILL LEAVE 8' CHASSIS UNMARKED AS DISCUSSED ON THE TELEPHONE. A-2 (40' CHASSIS) WITH 20' REFLECTIVE FROM END OF GOOSE NECK BACK AND ADD ADDITIONAL REFLECTIVE FOR GOOSENECK. B-1 (40/45' CHASSIS) SHOWS 50% OF THE REFLECTIVE FROM END OF GOOSE NECK TO END OF CHASSIS AND ONLY 6" PIECE WHITE REFLECTIVE AND DELINEATING FRONT OF CHASSIS. B-2 (40/45' CHASSIS) WHICH ADDS ADDITIONAL REFLECTIVE ON GOOSE NECK EQUALLY SPACED. WHEN I SPOKE ON THE TELEPHONE WITH YOU AND PAT BOYD, YOU INDICATED THAT AT LEAST 50% OF THE TOTAL LENGTH CHASSIS IN REFLECTIVE MATERIAL IS PLACED BEHIND THE GOOSE NECK. SINCE THE LOAD COVERS THE GOOSE NECK, YOU DID NOT SEE ANY NECESSITY IN PUTTING REFLECTIVE ON THE GOOSE NECK. HOWEVER, AT TIMES, A CHASSIS DOES MOVE WITHOUT A LOAD, AND THIS IN OUR OPINION, WILL CREATE A HAZARD, BECAUSE YOU WILL HAVE AN AREA OF 96" OR EVEN MORE DEPENDING ON DESIGN, WHICH WILL NOT HAVE ANY REFLECTIVE SHEETING ON IT. IT WOULD BE OUR SUGGESTION THAT YOU RE-EVALUATE YOUR POSITION FOR NOT MAKING IT MANDATORY THAT REFLECTIVE SHOULD BE APPLIED ON THE GOOSE NECK. I DISAGREE WITH THIS- 50% OF OVERALL LENGTH EVENLY SPACED FROM FRONT TO REAR (INCLUDING GOOSENECK) WITH A TOTAL OF 24'4" FOR A 48 FT. CHASSIS. CHASSIS DO TRAVEL WITHOUT CONTAINERS AND WOULD THEN CREATE A SAFETY HAZARD WHEN: 1) ON THE HIGHWAY BY HAVING AN 8 TO 10 FOOT GOOSENECK NOT IDENTIFIED CREATING A SPACE THAT COULD BE CONFUSING TO A MOTORIST. 2) IN THE CONTAINER YARDS WHEN CHASSIS ARE OFF LOADED. SEVERAL INCIDENTS HAVE BEEN REPORTED WHERE A PANEL TRUCK WILL RIDE UNDER THE NOSE OF CHASSIS DRIVING IT THROUGH THE WINDSHIELD. FINALLY WE UNDERSTAND THAT PAT BOYD HAS ADDRESSED THE ISSUE THAT NO MORE THAN FOUR FEET OF UNIDENTIFIED AREA SHALL BE ALLOWED ON A CHASSIS. OBVIOUSLY THE 8 to 10 FEET OF GOOSENECK WOULD BE IN VIOLATION OF THAT STATEMENT, FOR CHASSIS OFFLOADED ON A HIGHWAY. |
|
ID: nht80-1.44OpenDATE: 04/03/80 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Aveco Trucks of North America, Inc TITLE: FMVSS INTERPRETATION TEXT: This is in response to your request for an interpretation of Federal Motor Vehicle Safety Standard 101-80, Controls and Displays. You described a bulb check button which could be activated at any time by merely pushing it in, but which when released would be automatically deactivated. You asked whether the possible activation of this button at any time would take it out of compliance with section 5.3.1 of Safety Standard 101-80. This section states that "a telltale shall not emit light except. . . during a bulb check upon vehicle starting." This provision was intended to prevent the driver from accidently leaving the bulb check control activated and thereby creating a situation where a defective functioning of the vehicle would go unnoticed by the driver. Since the bulb check control that you described cannot accidently be left in the on position since it is deactivated when the driver releases it, section 5.3.1 of Safety Standard 101-80 would not operate so as to prohibit use of this device. I hope that you have not been inconvenienced by our delay in sending you this response. |
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.