
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: nht95-7.11OpenTYPE: INTERPRETATION-NHTSA DATE: October 3, 1995 FROM: Tom Byrne -- Vice President, Goodridge (USA) Inc. TO: John Womack -- Acting Chief Counsel, NHTSA TITLE: NONE ATTACHMT: 12/12/95 letter from Samuel J. Dubbin to Tom Byrne (Redbook (2); Std. 106) TEXT: Goodridge (UK) Ltd. has been awarded approval/certification for its Brakelines by the TUV Manheim, Germany. The test procedures and requirements were those of FMVSS 106. We are therefore now able to offer Stainless Steel Braided Brakelines that are legal for Street and Highway use in Europe and we believe the United States. We have completed the necessary paperwork and have filed for a USA DOT Manufacturers number. In order to avoid any possible confusion or irregularity, can you please confirm: * an independent laboratory certification that the line meets the requirements of FMVSS 106 is valid for the United States. * that such a brakeline can be used with an adapter into the master cylinder or caliper (for example, where pipe thread has been used). * are there any special marking requirements for the United States? We are required to tag with our manufacturers name, type of assembly and date of manufacture. I am submitting to you a copy of our TUV Certificate and an English translation. This is confidential material and I ask that you please give it confidential treatment. I thank you for your consideration of my request and look forward to your timely response. Please feel free to contact me at (408) 452-1664. |
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ID: nht95-7.12OpenTYPE: INTERPRETATION-NHTSA DATE: October 3, 1995 FROM: Ken Van Sciver -- President, Sciver Corporation TO: Chief Counsel -- NHTSA TITLE: NONE ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Ken Van Sciver (A43; Std. 206; VSA 102) TEXT: Safety Administration: The Sciver Corporation has developed a new product, the Auto Bib, hereafter known as product. We have already began the development and marketing of this new product. The reason for this letter is to familiarize ourselves to any local, state, or governing agency with regards to the consumers safety standards if applicable with this product. After speaking with Walter Meyers in one of your departments, he suggested we submit drawings and describe our product to the New Product Safety Committee for review. We have enclosed a promotional sheet that gives detailed instructions of it's uses and installation of this product. The intentions of this product are to provide the consumer a way of protecting their vehicle's door from the abuse caused by their small pets, the sun, and children. If you could please forward any information and findings at your earliest convenience it will be appreciated. Enclosures: product description product installation instructions (Enclosures omitted.) |
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ID: nht95-7.13OpenTYPE: INTERPRETATION-NHTSA DATE: October 9, 1995 FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA TO: Guy Dorleans -- International Regulatory Affairs Manager Valeo TITLE: NONE ATTACHMT: Attached to 9/29/95 letter from Guy Dorleans to NHTSA Chief Counsel TEXT: Dear M. Dorleans: This responds to your letter of September 29, 1995, with respect to the use of light-emitting diodes (LEDs) to fulfill the lighting requirements of Standard No. 108. You have enclosed a design for a lamp incorporating tail, stop, and rear turn signal functions, the illumination for which will be provided by red LEDs. At night, the LEDs will provide sufficient illumination to meet taillamp photometrics, with increased illumination when the brake pedal is applied, "so that the sum of the photometrics of the stoplamp and the tail lamp is fulfilled." When the turn signal is activated, "all the diodes are energized at full intensity during the on-period of the turn signal (and) the sum of the photometrics of the rear turn signal lamp and the tail lamp is then fulfilled. . . ." You ask for "confirmation that this new lighting combination is correct." We consider this lamp, as you have more fully described it in your letter, to be an acceptable design for meeting the requirements of Standard No. 108. If you have any questions, you may refer them to Taylor Vinson of this Office (phone: 202-366-5263). |
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ID: nht95-7.14OpenTYPE: INTERPRETATION-NHTSA DATE: October 9, 1995 FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA TO: Yoshiaki Matsui -- Manager, Automotive Equipemnt, Legal & Homologation Section, Stanley Electric Co. TITLE: Accessory Lamp with LEDs ATTACHMT: Attached to 9/18/95 letter from Yoshiaki Matsui to NHTSA Chief Counsel TEXT: Dear Mr. Matsui: This responds to your letter of September 18, 1995, describing a combination tail, stop, and rear turn signal lamp which incorporates incandescent bulbs to perform assigned functions, and which contains light-emitting diodes (LEDs) in a compartment along the outboard side. With respect to red LEDs adjacent to the tail and stop lamp, you state that the lamp is designed to conform to Standard No. 108 using the incandescent bulbs only, and that your regard the LEDs as an "accessory" acceptable to NHTSA (Your Question 1). We agree. Because the LEDs are not necessary to conformance with Standard No. 108, they are considered supplemental lighting equipment. Such equipment is permitted by paragraph S5.1.3 of Standard No. 108 if it does not impair the effectiveness of lighting equipment required by Standard No. 108. You state that when the taillamp and LEDs are lit simultaneously, the total intensity does not exceed the maximum intensity specified for a one-section taillamp. It would therefore appear that the presence of the LEDs does not impair the effectiveness of the taillamp (or the stop lamp, which will have a higher intensity). The red LEDs will provide a red color through the amber lens that covers the turn signal lamp, and will remain on when the turn signal is activated (Your Question 2). This design also appears permissible. We have never considered contiguous rear steady-burning red and flashing amber lamps to be prohibited by Standard No. 108 (the basic design of your lamp), and we do not believe that the supplemental red LEDs will impair the effectiveness of the amber turn signal lamp. If you have any further questions, you may refer them to Taylor Vinson of this Office (phone: 202-366-5263). |
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ID: nht95-7.15OpenTYPE: INTERPRETATION-NHTSA DATE: October 9, 1995 FROM: Rita Cola Carroll, M.A. -- Chairperson, Bus Safety Committee, Great Valley School District, Paoli, PA TO: Office of Chief Council for the NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 11/21/95 LETTER FROM Samuel J. Dubbin to Rita Cola Carroll (A43; Std. 222) TEXT: Dear Sir or Madam, I represent the Bus Safety Committee from Great Valley School District in Southeastern Pennsylvania. I would like to request a formal written response to the following question. If a child is not sitting fully in a school bus seat, that is, a child's body is partially extending into the aisle, is the child afforded the protection of the bus compartment in accordance with the Federal Motor Vehicle Safety Standard 222? A rapid response to this question would be most welcome. Sincerely, |
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ID: nht95-7.16OpenTYPE: INTERPRETATION-NHTSA DATE: October 10, 1995 FROM: Edward Mansell -- Chief Engineer, Polar Tank Trailer, Inc. TO: Philip R. Recht -- Chief Counsel, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 12/1/95 LETTER FROM Sanuel J. Dubbin to Edward Mansell (Redbook 2; Std. 108) TEXT: Dear Mr. Recht, We are requesting and interpretation of the language included in Federal Motor Vehicle Safety Standard No. 108 Lamps, reflective Devices and Associated Equipment, paragraph S5.7 Conspicuit Systems. The NHTSA has made it clear that the exact location and configuration of conspicuity sheeting is subject to variation based on the practicability of installation. Our request involves the practicability of installation of conspicuity sheeting on the rear of some Food Grade Tank Trailers (FGTTs). Paragraph S5.7.1.4.1(a) calls for sheeting to be placed across the full width of the trailer as close as practicable to 1.25 meters above the road surface. For many tank trailers the rear bumper, located approximately 0.5 m above the road surface, is the closest practicable location for installation of conspicuity sheeting. For some FGTTs, however, rear-mounted load/unload ports, pumps and valves are located directly above the center portion of the rear bumper. Conspicuity sheeting affixed to a bumper under the load/unload ports is subjected to repeat exposure to hot water as run off from wash downs cascades over the sheeting. Typically this area is washed at least once per day with water up to 200 degrees F. This repeated exposure to hot water degrades the conspicuity sheeting. Modes of failure include: loss of red coloring; delamination; loss of brightness; bubbling; cracking; and loss of adhesion. The deleterious effects of this exposure is evident regardless of the manufacturer of the sheeting. Analysis shows that sheeting applied to the rear of trailers with designs which do not result in the cascade of hot water over the sheeting do not experience these problems. P2 We interpret paragraph S5.7.1.4.1(a) to allow, that since installation of sheeting in a location subject to frequent hot water run off is not practicable, in the case of FGTTs with designs which results in water cascading from the load/unload area over the center fo the rear bumper, the sheeting may be applied from the extreme ends of the bumper to points no more than 6 inches (150mm) to the left or right of the area directly below the load/unload area. Further, for FGTTs which use a cabinet to enclose the load/unload area, conspicuity sheeting should be mounted on the cabinet doors to augment the sheeting on the bumper. Otherwise, the center section of the sheeting should be located on the tank, above the load/unload area. We believe that this proposal meets the intent of Standard 108 by delineating the rear of FGTTs without requiring manufacturers to redesign trailers to redirect the flow of wash water. We look forward to your interpretation of the Standard and await your reply. |
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ID: nht95-7.17OpenTYPE: INTERPRETATION-NHTSA DATE: October 11, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Thomas K. O'Connor -- Chief of Maintenance and Operations, Metropolitan Water Reclamation District of Greater Chicago TITLE: NONE ATTACHMT: ATTACHED TO 8/3/95 LETTER FROM THOMAS K. O'CONNOR TO NHTSA (OCC 11189) TEXT: Dear Mr. O'Connor: This responds to your letter asking about seat belt requirements for a step van with a GVWR greater than 10,000 pounds. You asked whether lap belts versus lap/shoulder belts are needed for compliance with the Federal motor vehicle safety standards. As discussed below, either lap belts or lap/shoulder belts may be used for this type of vehicle. The National Highway Traffic Safety Administration's safety belt installation requirements are set forth in Standard No. 208, Occupant Crash Protection. I note that this standard specifies requirements based on vehicle type and seating position within the vehicle. Different requirements also apply depending on the GVWR of the vehicle. The requirements for trucks with a GVWR of 10,000 pounds or more are set forth in S4.3.2 of Standard No. 208. That section provides vehicle manufacturers a choice of two options for providing occupant crash protection. Option 1, dealing with automatic crash protection, is not relevant to your inquiry. Option 2, set forth in S4.3.2.2, requires vehicle manufacturers to install Type 1 (lap) or Type 2 (lap/shoulder) belts at every seating position. Thus, either lap or lap/shoulder belts may be used to meet S4.3.2. I hope this information is helpful. If you have any further questions, please feel free to call Edward Glancy of my staff at (202) 366-2992.
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ID: nht95-7.18OpenTYPE: INTERPRETATION-NHTSA DATE: October 11, 1995 FROM: Gerald R. Stewart -- Office of Safety Performance Standards, Crash Avoidance Division, NHTSA TO: Office of the Chief Counsel, NHTSA TITLE: Request for Interpretation for Safety Grooves ATTACHMT: Attached to 11/13/95 letter from Samuel J. Dubbin to Borje Kukka (A43; Std. 104; Std. 205) TEXT: MEMORANDUM: At a recent meeting I received a video tape and brochures on safety grooves which are used in Finland and other countries to help keep windshields and wiper blades clean in adverse weather. Mr. Borje Kukka from Helsinki Finland asked for help with regard to which vehicle safety standards, if any, would be applicable to safety grooves. I have sent Mr. Kukka a letter with most of the information he needs; however Mr. Felrice suggested that I request an interpretation from Chief Counsel to be sent to Mr. Kukka so that he has a complete understanding of whether safety grooves are considered an item of vehicle equipment or not. I am submitting the video tape, brochures, and a copy of my letter to Mr. Kukka. Please prepare an interpretation letter for Mr. Kukka. If you have questions contact me at 366-5268 or Mr. Kukka at the following: Borje Kukka Humalistonkatu 5 00250 Helsinki Finland Phones: 011 358 0 493 013 private 011 358 02 419 820 Fax 011 358 0 407 315 cellular 011 358 49 414 727 Attachment Mr. Borje Kukka Humalistonkatu 5 00250 Helsinki Finland Dear Mr. Kukka, Thank you for inviting me to your meeting with Mr. Nitze to review the safety groove principles and video tape. I was impressed with the simplicity of the process for grinding the grooves into a vehicle windshield and also with the performance of the grooves on keeping the windshield and wiper blades clean during adverse conditions. I contacted the Office of Chief Counsel and a search of interpretations produced an example for a device which cleans windshield wipers. A copy is attached along with some general information which will help you. As I said in the meeting, it is important for you to understand the term "render inoperative" as it refers to our Federal Motor Vehicle Safety Standards 205 and 104. Copies of these are attached. At the meeting I gave you a copy of the ANS 226 document which is referenced by Standard 205. At this point, it is important for you to know whether the safety grooves would be considered by our agency as an item of motor vehicle equipment or not. I have provided your video tape and brochures to the Chief Counsel Office with a request for an interpretation of the question of which vehicle safety standards, if any, are applicable to your safety grooves. An answer should be available within 60 days. Thank you again for giving me an opportunity to learn about a simple process that can improve a driver's ability to drive safely. I hope this information is helpful to you. If you have questions or need more information please do not hesitate to call me at 202-366-5268. |
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ID: nht95-7.19OpenTYPE: INTERPRETATION-NHTSA DATE: October 11, 1995 FROM: A.D. Fisher TO: John Womack, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 11/21/95 LETTER FROM Samuel J. Dubbin to A.D. Fisher (A43; Std. 108) TEXT: Dear Mr. Womack: Enclosed are two documents covering the operation, features and highway safety attributes of a modified, rear, third signal light for private and commercial vehicles. We have been advised by Mr. Blane Laubis, of NHTSA, to forward this to you for your evaluation. Please furnish us with your interpretation and comments about this product, including its use application, as applied to Federal Motor Vehicle Safety Standard (FVMSS) #108. Thank you very much for your time and consideration. Sincerely, Enclosures THE ENLIGHTNER Update May 31, 1995 "The Enlightner" replaces the third, center, high-mounted brake light as used in most modern day vehicles. The light (or lens) has two colors, Red and Amber. The top half of the lens is Amber and the bottom half is Red. Amber signals "Caution" and the Red signals "Stop" to the driver of the vehicle following a vehicle equipped with "the Enlightner". Functions of "The Enlightner": 1. The Red portion is lighted when the brake pedal is applied, with the ignition "ON" or "OFF". This function overrides all other functions. 2. The Amber portion is lighted when the transmission selector lever is in any forward position with the accelerator pedal and the brake pedal not depressed. When the brake or accelerator pedals are depressed, the Amber light is "OFF".
When the transmission lever is in Reverse position, the Amber light flashes constantly at the rate of 90 flashes per minute. The flashing is continuous regardless of accelerator pedal and brake pedal positions as long as the transmission selector lever is in Reverse position. This give a warning to everyone behind the vehicle that it is in Reverse and it about to back up or is backing up. When the accelerator pedal is released ("OFF"), the Amber portion comes "ON", giving a "Caution" signal to the driver of the vehicle behind the vehicle equipped with "The Enlightner" that deceleration is taking place. When the accelerator and brake are not in use, the Amber portion is lighted. When power is reapplied by depressing the accelerator, the Amber light goes "OFF". When deceleration is taking place, Amber is "ON". When the brakes are applied, Amber goes "OFF" and Red comes "ON". The advantages of "The Enlightener" over similar products is that it keeps the driver following behind totally informed (enlightened) as to the functions of the vehicle ahead. "The Enlightener" will reduce rear-end collisions (one of the most common accidents) and reduce highway traffic injuries and fatalities. Signed by Alfred D. Fisher Date June 1, 1995 Witnessed by Debra A. Thompson Date June 1, 1995 "The Enlightener" According to U.S. Government statistics, there are over 10,000,000 highway accidents annually costing Americans $98,100,000,000 with an average cost per accident of over $9,800. Of the 10 million accidents, 25.3%, or approximately 2 1/2 million, are rear-end collisions. The average reaction time, from the instant the brake signal on a vehicle is seen until the brakes on the vehicle following it are applied, is 3/4 of a second. At 60 miles per hour, a vehicle travels 66 feet in 3/4 of a second. After the brakes are applied, the stopping distance for a car travelling at 60 MPH is a minimum of 146 feet. Therefore, the total distance from seeing the brake signal to a full stop is at least 212 feet. Introducing "The Enlightener"......... featuring a Deceleration Caution Signal (DCS) in addition to the traditional third brake light. The instant the vehicle accelerator pedal is released and before the brake is applied, "The Enlightener" signals deceleration or a change of vehicle operation. It is estimated that the use of "The Enlightener" will reduce rear-end collisions over 41% and prevent thousands of highway injuries and fatalities. The reduction in costs to Americans would exceed $10.1 Billion annually. In addition to the Deceleration Caution Signal (DCS), other features of "The Enlightener" include the DCS being illuminated when the vehicle is in any mode other than stopping or normal forward motion, and a flashing caution light when the vehicle transmission selector lever is in reverse position. "The Enlightener" is truly a unique innovation for improving highway safety that will save hundreds of lives, prevent thousands of injuries and save Americans billions of dollars annually. |
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ID: nht95-7.2OpenTYPE: INTERPRETATION-NHTSA DATE: September 25, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Karey Clock -- Moriden America, Inc. TITLE: NONE ATTACHMT: ATTACHED TO 8/7/95 LETTER FROM KAREY CLOCK TO JOHN WOMACK (OCC 11120) TEXT: Dear Ms. Clock: This responds to your inquiry about testing procedures in Federal Motor Vehicle Safety Standard No. 302, Flammability of Interior Materials. In particular, you asked whether certain materials, which you list as flat woven, double raschel, tricot, and moquette, should be tested by using support wires. The short answer is that during NHTSA compliance testing, support wires may be used in testing any specimen that "softens or bends at the flaming end so as to cause erratic burning." However, the agency cannot specify, outside of the context of a compliance test, whether a given type of material falls in this category. By way of background information, NHTSA is authorized to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. You ask about Standard No. 302, which specifies requirements for the flammability resistance of materials in the occupant compartment of new vehicles. Along with specified performance requirements, Standard No. 302 sets forth conditions and procedures under which NHTSA tests materials for compliance with the standard. Section S5.1.3 of the standard states, in relevant part, that The test specimen is inserted between two matching U-shaped frames of metal stock 1-inch wide and 3/8 of an inch high. The interior dimensions of the U-shaped frames are 2 inches wide by 13 inches long. A specimen that softens and bends at the flaming end so as to cause erratic burning is kept horizontal by supports consisting of thin, heat resistant wires, spanning the width of the U-shaped frame under the specimen at 1-inch intervals. A device that may be used for supporting this type of material is an additional U-shaped frame, wider than the U-shaped frame containing the specimen, spanned by 1 -- mil wires of heat resistant composition at 1-inch intervals, inserted over the bottom U-shaped frame. You ask whether certain specific types of materials could be tested using the supplemental wire described in S5.1.3. The agency uses supplemental wires when there is a reasonable expectation that a test specimen will soften and bend while burning. The agency bases its determination about the likelihood of softening and bending on observations made in previously-conducted compliance tests of the specimen, or on the agency's knowledge of or testing experience with components that are highly similar to a test specimen. However, since a decision to use wires is made only in the context of compliance testing, we regret that we cannot tell you at this time whether support wires will be used to test the materials you listed. Vehicle manufacturers are not required by Standard No. 302 to test the flammability of their vehicles in the manner specified in the standard. The standard only sets the procedure that the agency will use in its compliance testing. Thus, a vehicle manufacturer is not required to use wires only with specimens that are anticipated to soften or bend. However, vehicle manufacturers must exercise due care in certifying that their product will meet Standard No. 302's requirements when tested by NHTSA according to the specified procedures of the standard. Whether a vehicle manufacturer has met that due care standard when using support wires in situations other than those described in Standard No. 302 is a matter that can be determined only in the context of an enforcement proceeding. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw at this address or by phone at (202) 366-2992. |
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.