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 |
|---|---|
| search results table | |
ID: 13622.ztvOpen The Honorable David L. Hobson Attention: Bob Clark Dear Mr. Hobson: This responds to your letter of December 20, 1996, to Ms. Carmen Rivers-Glagola of the Department, on behalf of your constituent, Stephen Reeves of Chillicothe. According to Mr. Reeves' letter to you dated December 12, he seeks "waivers or a change in the law for vehicle length." None of the Federal motor vehicle safety standards, laws, or other regulations of this agency establish limits on the length of a motor vehicle. Federal Highway Administration regulations impose certain length limits on combination vehicles with two or more cargo-carrying units (see 49 CFR 658.23 and Appendix C to Part 658). Most of the states also enforce overall length limits on straight trucks, but we are not conversant with state laws and therefore cannot advise you on this point. We suggest that Mr. Reeves contact the Ohio Department of Motor Vehicles in Columbus to see whether your state has or knows of restrictions of this nature. It should be noted, however, that Mr. Reeves' unwillingness to be specific about the vehicle in question makes it difficult to answer his question precisely. If Mr. Reeves has been misinformed about our regulations, we would be pleased to try to clarify the matter for him. He may telephone Taylor Vinson of the Office of Chief Counsel at (202) 366-5263. Sincerely, John Womack Acting Chief Counsel ref:571 d:4/14/97 |
1997 |
ID: 13705cos.coOpen Mr. Terry Emerson Dear Mr. Emerson: This responds to your December 6, 1996 letter asking for confirmation that S5.2.3.2 of Standard 213, "Child Restraint Systems," does not apply to booster seats. Your question relates to a petition for exemption for inconsequential noncompliance that Cosco submitted in July 1996 with the understanding, which you now believe to be incorrect, that S5.2.3.2 applies to those seats. Because you now believe S5.2.3.2 does not apply, you believe there is no noncompliance at issue and wish to withdraw the petition. You are correct that the booster seats are not subject to S5.2.3.2. S5.2.3.2, which requires that surfaces contacting a dummy's head must be covered with energy absorbing foam, applies by way of S5.2.3.1 to child restraint systems (other than child harnesses) that are recommended for children whose masses are less than 10 kg (weighing less than 22 lb). Those restraints are infant-only and convertible restraints. You state that the booster seats in question are recommended for children whose masses are from 13.6 kg to 27 kg (weighing 30 to 60 lb).(1) Given that recommended range for the boosters, S5.2.3.2 does not apply. We consider your petition to be withdrawn, as you request, and will take appropriate steps to close the action. If you have any questions, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely, John Womack ref:213 1. This accords with S5.5.2(f) of Standard 213, which prohibits booster seats from being recommended for children whose masses are less than 13.6 kg. |
1997 |
ID: 13720.mlsOpen Mr. Gunnar Almen Dear Mr. Almen: This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 105, Hydraulic Brake Systems (49 CFR 571.105). You stated that as the national testing agency for vehicles imported into Sweden, you need to know U.S. regulations for asbestos free brake linings. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized under Title 49, Chapter 301 of the U.S. Code to issue FMVSSs that set performance requirements for new motor vehicles and new items of motor vehicle equipment. NHTSA does not approve or certify any vehicles or items of equipment, as is the practice in Europe. Instead, Chapter 301 establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency has used this authority to issue FMVSS No. 105, which specifies requirements for hydraulic service brake and associated parking brake systems. This Standard does not contain any provision requiring or prohibiting asbestos free brake linings. While most brake linings are asbestos free, some brake linings sold in the aftermarket have asbestos. Please note that the United States Environmental Protection Agency (EPA) has issued rules prohibiting the use of asbestos brakes. We have forwarded your letter to Mr. Mike Matthiesen, Chemical Management Division, Office of Pollution Prevention and Toxics, EPA, 401 M Street, SW, Washington DC 20460. He should be able to explain how EPA's rules apply to asbestos brakes. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. Sincerely,
Chemical Management Division Office of Pollution Prevention and Toxics, EPA, 401 M Street, SW, Washington DC 20460 ref:105 |
1997 |
ID: 13945.ztvOpen Mr. Tom L. Ricca Dear Mr. Ricca: This is in reply to your letter of January 20, 1997, asking for an interpretation of Federal law and regulations as they may apply to your invention, the "LightGenie." According to the product literature you enclosed, your invention has the following features. The first is a "40-Second Delay Turnoff"; when the engine is stopped and the ignition key removed while the main lighting switch is on, the lights will be automatically extinguished after 40 seconds. The second feature is "4-Minute Delay Turnoff." When the engine is off, turning the light switch to on will cause the lights which are controlled by the switch to be turned on for four minutes continuously, and then automatically turned off. The third feature is called "4-Hours Blinking Delay Turnoff." Under this feature, when the vehicle engine is stopped, the parking lamps, and headlamps if desired, will blink automatically for four hours before turning off automatically. These three features are acceptable under our law and regulations. The fourth feature is "Daytime Running Lights", or DRLs as we call them. Whenever the engine is running, the upper beam headlamps will be on, to be extinguished 10 seconds after the engine stops. In addition, the intensity of the headlamps is lowered during the day to avoid glare to other drivers. The lamps switch to lower beam and the parking lamps are illuminated if the outside ambient light level falls below a certain level. However, the main light switch of the vehicle has to be in the headlamp-on position in order for the DRL feature to function. You believe that the LightGenie may not comply with S5.5.11(a) of Standard No. 108 "which can be interpreted as to prevent the production of dangerous glare into the eyes of other drivers by the addition of the on state of either lower beams or upper beams of the headlamps which are not intended to operate as DRL." You would like an interpretation of S5.5.11(a) which would permit your system to be used. You wish to market the LightGenie in both the OEM and aftermarkets. As you know, DRLs are not required items of original lighting equipment. But once a manufacturer chooses to offer a system that employs lamps on the front of a vehicle that are illuminated during daylight hours, that system must comply with paragraph S5.5.11(a). Paragraph S5.5.11(a)(1) establishes general illumination requirements that do not apply if the DRL system is "(i) a lower beam headlamp intended to operate as a DRL at full voltage . . .; or (ii) an upper beam headlamp intended to operate as a DRL, whose luminous intensity at test point H-V is no more than 7,000 candela . . . ." As we understand it, the LightGenie activates the upper beam headlamps at something less than full intensity during the daytime, switching to full lower beam intensity under low ambient level light conditions. We interpret S5.5.11 as requiring headlamps used as DRLs to be operated in either the upper beam or lower beam mode as specified above, but not permitting switching between upper and lower beam modes. For this reason, your system would not comply with the specifications for OEM DRLs. However, there is another reason as well. S5.5.11(a) presently requires automatic deactivation of DRLs "when the headlamp control is in any 'on' position . . . ." Your system requires the headlamp control to be in the "on" position in order to operate. You have asked that we read S5.5.11(a)to require deactivation of DRLs "when any upper beams or lower beams of the headlamps which are not intended to be operated as DRL are turned on continuously . . . ." As a practical matter, we do not see how the vehicle's headlamp system could be operated as a headlamp system if the control must be in the "on" position for the LightGenie to operate. As a legal matter, you are requesting in effect an amendment of S5.5.11(a) beyond the limits of an interpretation. As an aftermarket device, the LightGenie might be usable on vehicles that were not originally equipped with DRLs as long as it allows the headlamp control to perform its original design function. However, the LightGenie would still have to comply with local laws in order to be operated within any State. We are unable to advise you on state laws, and suggest that you contact the Department of Motor Vehicles in the States. Finally, we call your attention to paragraph S5.5.11(a)(ii) which allows an upper beam headlamp to be used as a DRL only if two conditions are met: that the headlamp's luminous intensity at test point H-V is not more than 7,000 candela, and that the headlamp be mounted not higher than 864 mm above the road surface. This would appear to rule out use of the LightGenie using the upper beam of headlamp of some larger sport utility vehicles and trucks. If you have further questions, you may call Taylor Vinson at 202-366-5263. Sincerely, John Womack ref: |
1997 |
ID: 13946blt.adjOpen Ms. Christine S. Davik-Galbraith Dear Ms. Davik-Galbraith: This responds to your letter asking whether any of the regulations administered by the National Highway Traffic Safety Administration (NHTSA) apply to children's safety belt adjusters. To answer your question, I have enclosed copies of two of the letters we have written on this subject. These two are our response to Angela Caron, dated March 16, 1994, and to Brett Higgins, April 26, 1993. As explained in those letters, there is no safety standard that directly applies to safety belt adjusters. However, there are several provisions in NHTSA's statute that are relevant to those products, such as the responsibility borne by persons manufacturing safety belt adjusters to ensure that the products are free of safety-related defects. I note also that the American Academy of Pediatrics (AAP) petitioned this agency in January 1996 to amend Safety Standard No. 213 to regulate safety belt adjusters for children. Enclosed is a copy of the petition. NHTSA expects to respond to the AAP petition shortly. I hope this answers your questions. If you need further assistance, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely, John Womack Enclosures (3) |
1997 |
ID: 13951.wkmOpen Richard D. Teeple, Esq. Dear Mr. Teeple: Please pardon the delay in responding to your letter to me of January 17, 1997, in which you asked whether you would be permitted to add "CAN REPLACE LT235/75R15 (C)" to the size markings on the sidewalls of your 30x9.50R15LT size of Mickey Thompson Baja Radial MTX light truck tires. The answer is no, the addition would not comply with Standard No. 119. We addressed the issue of dual size markings on tires in a letter to Mr. Earl Dahl, Vice President, Goodyear Tire & Rubber Company, dated January 7, 1988, in which we quoted extensively from an interpretive letter to Michelin dated July 9, 1987 (copies enclosed). In both letters we stated that although dual-size markings were once a common practice in the industry, it confused many consumers as to the size of the tires on their vehicles. We pointed out that the purpose of Federally-required markings was to provide consumers with straightforward information for the safe use and operation of their tires. Thus, we concluded that it was "inappropriate" to permit a marketing technique that was confusing to many consumers, thereby defeating the purpose of the required tire markings. The agency continues to adhere to those interpretations, and still believes that dual size markings on tires are inappropriate. Accordingly, your proposed markings would not comply with Standard No. 119. We hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992, or by FAX at (202) 366-3820. Sincerely, |
1997 |
ID: 13960sew.labOpen Mr. Strawn Cathcart Dear Mr. Cathcart: This responds to your letter concerning the air bag warning label requirement adopted in Standard 213 by a November 27, 1996 final rule (61 FR 60206). I apologize for the delay in responding. The rule requires rear-facing child seats to have a specified label "permanently affixed to the outer surface of the cushion or padding in or adjacent to the area where a child's head would rest, so that the label is plainly visible or easily readable." S5.5.2(k)(4). You ask whether the standard would permit you to sew one side of the label in the fabric seam in the head area of the child seat cushion. You state that you have tried other methods of permanently affixing the label but each has been unsatisfactory. You state that heat transfer results in an illegible label, due to the uneven surface of woven fabrics. Sewing all four perimeter sides to the surface of the cushion causes wrinkling in the surface of the label, due to the thick foam to which the fabric is laminated, which can make the label difficult to read. You state that sewing one end of the label into the seam eliminates all of these problems. Our answer is that the label may not be sewn on only one side as you suggest. The air bag warning is, at this time, "the most important issue to communicate to consumers." 61 FR at 60214. NHTSA required the label to be where the child's head rests or adjacent to that area "to ensure that parents see the label each time they place the seat in a vehicle." Id. By virtue of its location and ease of detachment by cutting, tearing or pulling off a single row of stitching, the label you suggest invites removal. As such, we do not believe the label is likely to stay attached during the lifetime of the child restraint in satisfaction of the permanently affixed requirement of S5.5.2 (k)(4). If you have any further questions, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely, |
1997 |
ID: 13961.dfOpen Ms. Jane L. Dawson Dear Ms. Dawson: This responds to your letter asking about the meaning of "high-force" and "low-force access regions" in S5.3.3.2 of Federal Motor Vehicle Safety Standard No. 217 for school bus emergency exit windows, and the reason for the differing force requirements in the two access regions. I regret the delay in responding. S5.3.3.2 states:
The terms "high force" and "low force access regions" have been used in Standard 217 since 1972. S5.3.3.2 limits where release mechanisms for a window exit may be placed, and the force and motion needed to release the exit. The high force and low force access regions depicted in the figures show where release mechanisms may be located, and show, depending on where the release mechanism is located, which force and type of motion requirements apply. The idea underlying the exit release requirements is that if the direction of motion necessary to operate a release mechanism makes operating the mechanism relatively easy, and if the mechanism is within relatively easy reach, the force level necessary to operate the mechanism may be relatively high. Otherwise the force must be relatively low. You ask: "Does [the reference to the access regions] mean that release mechanisms located in the low-force region are limited to utilizing a rotary or straight motion and that release mechanisms located in the high-force region are limited to straight and perpendicular motion?" You are correct that among the requirements of S5.3.3.2 are that rotary or straight type motions must be used for release mechanisms located in regions of low force application and that a straight motion must be used for release mechanisms located in regions of high force application. If you have other questions, please call us at (202) 366-2992. Sincerely, |
1997 |
ID: 13962-1.pjaOpen Mr. R.H. Anderson Dear Mr. Anderson: This responds to your letter concerning our December 10, 1996, interpretation to your associate Mr. Thomas Joyce, regarding Federal Motor Vehicle Safety Standard No. 224, "Rear Impact Protection." I apologize for the delay in responding. You asked us to reexamine the letter as it would affect your tilt bed trailers. As we stated in the December 10 letter, to be excluded from Standard 224, work performing equipment on the vehicle must reside in or move through the area specified for the underride guard "while the vehicle is in transit." The quoted language means during the period that the vehicle itself is traveling over the road. Your letter appears to assume that because your frame rails are work performing equipment that move through the area specified for the underride guard, the special purpose vehicle exclusion must apply to your trailers. As the regulation is currently written, that is not so. The fact that the frame rails move out of that area while your vehicle is in transit and, as your letter says, cannot move through that area during transit, means that the exclusion does not apply to your vehicles. Under one of our regulations (49 CFR Part 555), vehicle manufacturers may apply for a temporary exemption from the Federal motor vehicle safety standards. Under Sec. 555.6(a), a manufacturer whose yearly production is not more than 10,000 units may ask for an exemption of up to three years on the basis that compliance would cause it substantial economic hardship and that it has attempted in good faith to comply with the standard from which it has asked to be excused. I have enclosed a copy of Part 555 for your information. Please note that it takes three to four months from the date of submittal before a decision can be made on such an application because it has to be submitted for public comment. I understand that you and Paul Atelsek of my staff discussed possible engineering solutions that you have not yet explored. If you need further assistance, please contact Mr. Atelsek at (202) 366-2992. Sincerely, d:7/17/97 |
1997 |
ID: 13967.wkmOpen Mr. Fred J. Turcotte Dear Mr. Turcotte: Please pardon the delay in responding to your letter to this agency recommending that auto manufacturers provide interior latches in trunk lids so that a person could escape if locked inside. You stated in your letter that many car hijackings, commonly called carjackings, are taking place and that in many instances, the perpetrator locks the victim in the trunk, then takes the victim to a remote place and murders him or her. You stated that an interior latch could provide the victim a means to escape. An interior latch may or may not be effective as a means of escaping from the trunk. The agency is concerned that criminals such as carjackers, knowing that there is an interior latch in the trunk, could disable the latch, or worse, incapacitate the victim before placing him or her in the trunk. In addition, we have no data on the number of deaths or injuries attributable to intentional or inadvertent entrapment in the trunk of a car. Accordingly, we have no basis at this time to issue regulations requiring latches on the insides of trunk lids. We will, however, continue to monitor our defect complaint files, and law enforcement data to be alert to potential problems of this nature. These are measures we normally take in our continuing efforts to improve motor vehicle safety. I hope this information is helpful to you, and thank you for your interest in motor vehicle safety. Sincerely, |
1997 |
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.