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: aiam1772OpenMs. Dianne Black, Liaison Engineer, British Leyland Motors Inc., 600 Willow Tree Road, Leonia, NJ 07605; Ms. Dianne Black Liaison Engineer British Leyland Motors Inc. 600 Willow Tree Road Leonia NJ 07605; Dear Ms. Black: This is in response to your letter of December 19, 1974, requestin interpretations of two test conditions contained in Standard No. 301-75, *Fuel System Integrity*.; Your first question relates to the static rollover test condition an asks whether it was the NHTSA's intention that the vehicle be rotated to three positions only for spillage measurement. (Paragraph S7.4 specifically refers only to increments of 90 degrees, 180 degrees, and 270 degrees.) The static rollover test is intended to test the amount of fuel spillage a vehicle experiences at each 90 degree increment in a full 360 degree rotation. The standard presumes that the test begin with the vehicle in an upright position. It is from this upright position that the vehicle begins its movement to the remaining three 90 degree increments.; Your second question asks for an interpretation of the section relatin to the operation of the vehicle's fuel pump during testing. Paragraph S7.1.3 of the standard requires that a electrically driven fuel pump be in operation during the barrier crash tests if it normally operates with the activation of the vehicle's electrical system. If pump operation requires the operation of the vehicle's engine, ten (sic) the pump should not be running during the barrier crash tests. If the fuel pump installed in your barrier is capable of independent operation as described in SF.1.3 it should be operating during the barrier crash tests even if it cuts off fuel at the moment of impact. Under the existing requirements, whether a pump out of fuel at impact would not be relevant to whether it must be operating at impact. Of course, over cutoff feature would be considered as pard of the bump's normal operation.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4120OpenMr. Sidney K. Saksenberg, Manager of Regulatory Affairs, CSA Limited, Inc., P.O. Box 690347, Houston, TX 77269-0347; Mr. Sidney K. Saksenberg Manager of Regulatory Affairs CSA Limited Inc. P.O. Box 690347 Houston TX 77269-0347; Dear Mr. Saksenberg: This responds to your November 12, 1985 letter to NHTSA's Office o Vehicle Safety Compliance, concerning the packaging requirements of Federal Motor Vehicle Safety Standard No. 116, *Brake Fluid*, You asked whether the brake fluid container you enclosed would comply with the standard. Your letter has been referred to my office for reply.; By way of background information, I must explain that NHTSA does no pass approval on the compliance of any vehicle or equipment with a safety standard before the actual events that underlie certification. Under the National Traffic and Motor Vehicle Safety Act, it is your responsibility as a manufacturer to determine whether your products comply with all applicable safety standards and regulations, and to certify your products in accordance with that determination. Therefore, the following interpretation only represents the agency's opinion based on your letter and enclosure.; The sample container you enclosed is plastic and has a resealable scre cap. The cap is attached to a plastic band, or ring, encircling the opening of the container, and the attachment is broken when the cap is twisted open. The cap itself is lined with an inner seal which you have indicated is impervious to the packaged brake fluid.; Standard No. 116 specifies performance and labeling requirements fo motor vehicle brake fluids and their containers. Paragraph S5.2.1 of the standard sets forth specific requirements for container sealing of brake fluid packages:; >>>Each brake fluid or hydraulic system mineral oil container with capacity of 6 fluid ounces or more shall be provided with a resealable closure that has an inner seal impervious to the packaged brake fluid. The container closure shall include a tamper-proof feature that will either be destroyed or substantially altered when the container closure is initially opened.<<<; The container you enclosed appears to be provided with a resealabl closure, i.e., the twist-off cap, and an impervious inner seal. The cap's tamper-proof feature is the attachment to the plastic ring that would be broken (and thus 'destroyed or substantially altered') when the cap is initially opened. Although not required by the standard. you have taken the commendable extra step of including a statement on the cap that warns purchasers not to accept the container if the seal is broken. We would suggest that you ensure that the warning is clearly legible.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1322OpenMr. William A. Teeling, Somerset Motors Inc., U.S. Highway 22, White House, NJ 08888; Mr. William A. Teeling Somerset Motors Inc. U.S. Highway 22 White House NJ 08888; Dear Mr. Teeling: This is in reply to your letter of October 15, 1973, concerning th means by which you can establish that the odometer on a car you have purchased has been reset.; Without detailed information about the car and about the circumstance which lead you to believe that the odometer has been altered, we can only offer a broad outline of the possible methods of proof. One source might be a former owner who had registered more miles on the odometer when he sold the car than are shown upon subsequent resale. Another source might be a repair shop or service station that had worked on the car and recorded its earlier mileage. A third source would be physical evidence on the car itself: excessive engine wear, excessive brake lining wear, or physical marks of tampering on the odometer or odometer cables. We would be interested to learn of the outcome of your situation.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2918OpenHonorable Bud Shuster, House of Representatives, Washington, DC 20515; Honorable Bud Shuster House of Representatives Washington DC 20515; Dear Mr. Shuster: This responds to your inquiry dated November 29, 1978, on behalf of on of your constituents, Mr. C. Stake, requesting information about Federal safety standards concerning door locks on automobiles. Specifically, Mr. Stake is concerned that the doors on his 1977 Mercury Monarch can be unlocked by a child from the inside by lifting the door handle.; I am enclosing a copy of Safety Standard No. 206 (49 CFR 571.206) which specifies performance requirements for side door locks and side door retention components to minimize the likelihood of occupants being thrown from the vehicle as a result of impact. That standard specifies that each door on a passenger car shall be equipped with a locking mechanism with an operating means in the interior of the vehicle. Paragraph S4.1.3.1 of the standard specifies that when the locking mechanism on a side *front* door is engaged, the outside door handle or other outside latch release control shall be inoperative. For side *rear* doors, however, paragraph S4.1.3.2 requires both the outside and inside door handles to be inoperative when the locking mechanism is engaged.; This latter requirement was specifically included in the standard t address Mr. State's concern, that is, to prevent children from unlocking rear doors by means of the door handle. The design restriction was limited to rear doors on the basis that the danger arises primarily with unattended children sitting in the rear seat. A child sitting in the front seat is likely under the watchful eye of the driver. Further, there is the consideration that in emergency situations the driver may need to unlock his front door as easily and quickly as possible.; Since the Standard No. 206 requirements have been in effect for som time, we assume that the situation Mr. Stake describes is true only of the front doors of his Mercury Monarch. As noted above, however, there are competing safety considerations involved with door locks on front side doors.; Please contact our office if your constituent has any further question concerning this matter, or have him contact us directly.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0925OpenMr. Steven M. Sharp, Managing Director, Intercontinental Equipment Corp., 5383 Overland Avenue, San Diego, CA 92123; Mr. Steven M. Sharp Managing Director Intercontinental Equipment Corp. 5383 Overland Avenue San Diego CA 92123; Dear Mr. Sharp: This is in reply to your letter of September 25, 1972. You hav enclosed a copy of a letter from Suzuki Motor Company, Ltd., dated September 14, 1972, in which it objects to the certification label that you propose to attach to Suzuki trucks imported by you for sale. The label shows Suzuki as the manufacturer and Intercontinental Equipment Corporation (IEC) as the importer of the trucks.; Suzuki bases its objection on the fact that: >>>'. . . the vehicles as manufactured by Suzuki does (sic) not confor to all applicable Federal Motor Vehicle Safety Standards *in effect on the date of manufacture*, and it will be misrepresentation by our company to make such statement.'<<<; Suzuki also comments 'the responsibility for compliance rests sorel (sic) on both IEC and Yachiyoda but this fact is not clearly shown on the label.'; This agency's position is that the certification scheme you hav described is an appropriate one for imported vehicles that have been modified after manufacture to conform to the standards.; We do not consider the certification label necessarily to be representation by the original manufacturer. The question of who is responsible for the correctness of the certification, and for conformity, must be decided on the facts of the individual case. In this case, the representation is by IEC, not Suzuki, and IEC is responsible for conformity of the vehicle.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1637OpenMr. Frank L. Wigand Jr., Engineering Department, Todco Division, 2195 Alpine Way, Hayward, CA 94545; Mr. Frank L. Wigand Jr. Engineering Department Todco Division 2195 Alpine Way Hayward CA 94545; Dear Mr. Wigand: This responds to Todco's September 27, 1974, question whether Standar No. 121, *Air brake systems*, 49 CFR 575.121, requires a spring brake system on Todco's 'Jifflox converter dolly.' You describe the Jifflox dolly as a trailer converter dolly which may also be used as a 'third axle attachment' on a two-axle truck.; Standard No. 121 applies to vehicles, and specifies separat requirements for trucks, buses, and trailers. It appears that the Jifflox is subject to separate requirements under the standard depending on its use.; If Todco manufactures and sells the Jifflox for use as a 'traile converter dolly' (defined in 49 CFR 571.3 as a trailer equipped with one or more axles, a lower half of a fifth wheel, and a drawbar), it constitutes a vehicle subject to Standard No. 121. As such it is exempted from the parking brake system requirements (S5.6) and its emergency braking capability is not required to be applied by an emergency source, such as a spring brake, that is not affected by loss of air pressure or brake fluid pressure in the service brake system.; If a truck manufacturer utilizes the Jifflox as an additional axle i the suspension of its vehicle, the truck manufacturer must assure that the truck meets the requirements applicable to it with the Jifflox incorporated in it. This means that, if the truck is manufactured to accept the Jifflox dolly and the truck is rated for a gross vehicle weight rating that depends on inclusion of the axle, the truck must comply with all applicable requirements of the standard with the Jifflox attached. If the truck manufacturer determines that parking brakes are required on the Jifflox axle to meet S5.6.1 or S5.6.2, those parking brakes would have to be applied by an energy source that is not affected by loss of air pressure or brake fluid pressure in the service brake system.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4435OpenThe Honorable Beverly B. Byron Member of Congress U.S. House of Representatives Westminster District Office 6 North Court Street Westminster, MD 21157; The Honorable Beverly B. Byron Member of Congress U.S. House of Representatives Westminster District Office 6 North Court Street Westminster MD 21157; "Dear Ms. Byron: Thank you for your recent letter on behalf of you constituent, Mr. Joseph L. Ciampa, Jr., who received a citation from the Maryland State Police, Automotive Safety Enforcement Division, for noncomplying window tinting. You asked us to review Mr. Ciampa's letter and provide you with our comments and appropriate information. I am pleased to have the opportunity to do so. Mr. Ciampa suffers from diabetes, which makes his eyes extremely sensitive to sunlight. Because of this, the side windows on his passenger automobile apparently were tinted such that the tinted glazing no longer complied with State of Maryland requirements. There is no indication whether Mr. Ciampa did the tinting on his own or had an aftermarket business do it. According to Mr. Ciampa's letter, he was previously given a medical exemption by the State of Maryland that permitted him to drive with windows tinted differently than Maryland law permits. However, Mr. Ciampa stated that Maryland officials have now told him that the Federal government will not allow Maryland to grant any more medical exemptions. This information is inaccurate. Some background information on the Federal requirements in this area may be helpful. Our agency, the National Highway Traffic Safety Administration (NHTSA) is authorized, under the National Traffic and Motor Vehicle Safety Act, to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. The safety standard that specifies performance and location requirements for glazing used in vehicles is Standard No. 205, Glazing Materials (49 CFR 571.205). These requirements include specifications for minimum levels of light transmittance (70 percent in areas requisite for driving visibility, which includes all windows in passenger cars). Under Standard 205 no manufacturer or dealer is permitted to install solar films and other sun screen devices in a new vehicle, without certifying that the vehicle continues to be in compliance with the light transmittance and other requirements of the standard. Federal law does not permit States to grant any exemptions, including medical exemptions, from the safety standards. Thus, we assume that Mr. Ciampa's car as delivered to him complied with Standard No. 205's requirement for at least 70 percent light transmittance in all of its windows, including the side windows that are now the subject of dispute. The requirement that a car comply with all applicable safety standards applies only until the car is first sold to a consumer. After a vehicle is first sold to a consumer, any modifications to the vehicle's windows, including the tinting performed on the side windows of Mr. Ciampa's car, are affected by section 108(a)(2)(A) of the Safety Act. That section prohibits any manufacturer, dealer, distributor, or repair business from 'rendering inoperative' any device or element of design installed in a vehicle in compliance with any safety standard. In the case of windows in a passenger car, this means that no manufacturer, dealer, distributor, or repair business could install a sun screen device or window tinting that would result in a light transmittance of less than 70 percent for any window of the car, or otherwise cause the car to no longer comply with the other requirements of Standard No. 205. Violations of this 'render inoperative' prohibition can result in Federal civil penalties to the manufacturer, dealer, distributor, or repair business of up to $1000 for each noncomplying installation. Again, Federal law does not permit States to grant any exemptions, including medical exemptions, from the 'render inoperative' prohibition in Federal law. Thus, the State of Maryland does not have any authority to permit manufacturers, distributors, dealers, or repair businesses to install tinting on the side windows of passenger cars if such tinting causes those windows to have less than 70 percent light transmittance. Instead, the manufacturer, distributor, dealer, or repair business that installed such tinting on Mr. Ciampa's side windows would be liable for the civil penalty discussed above. Please note that Federal law does not affect vehicle owners. Vehicle owners may alter their own vehicles and operate them on the highways as they please, even if the vehicle's windows no longer comply with the requirements of Standard No. 205. Hence, no provision of Federal law or this agency's regulations prevents Mr. Ciampa himself from tinting his side windows. However, each of the individual States has the authority to regulate the modifications that may be made to vehicles by their owners and to establish requirements for vehicles to be registered or operated in that State. It would seem that the State of Maryland has exercised its authority to prohibit windows being tinted in the way that Mr. Ciampa's are. The wisdom and fairness of applying that prohibition to individuals with Mr. Ciampa's condition is something to be decided by the State of Maryland, not the Federal government. Contrary to the statement in Mr. Ciampa's letter, we have never told Maryland or any other State how to administer their laws and regulations with respect to the operational use of vehicles in the State. I hope this information is helpful. If you have any further questions or need some more information on this subject, please do not hesitate to contact Ms. Susan Schruth of my staff at this address, or by telephone at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel cc: Washington Office Constituent's Correspondence"; |
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ID: aiam1267OpenMr. J.C. Barford, President, JCB Plastics, Ltd., 655 Garrison Road, Fort Erie, Ontario; Mr. J.C. Barford President JCB Plastics Ltd. 655 Garrison Road Fort Erie Ontario; Dear Mr. Barford: This is in reply to your letter of August 22, 1973, asking whether th American National Standards Institute (ANSI) Standard Z90.1-1971 will apply to the manufacture of helmets until the March 1, 1974 effective date of Standard No. 218, 'Motorcycle Helmets.'; The Z90.1-1971 Standard is not a Federal Motor Vehicle Safety Standar and, therefore, could only apply to helmets manufactured or sold in those States that have adopted it, and then only until the effective date of the Federal standard. For information regarding Ontario's requirements for the manufacture of helmets, I suggest you contact the Ontario Bureau of Motor Vehicles. As you indicate, any U.S. State or local requirements for the design or performance of motorcycle helmets, that have a bearing on safety, will have to be identical to the requirements of the Federal standard when it becomes effective.; I have enclosed a copy of Standard No. 218 pursuant to your request. Yours Truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4065OpenMr. Shintaro Nakatasuka, Manager, Certification Business Dept. II, Mazda Motor Corporation, P.O. Box 18, Hiroshima 703 91, JAPAN; Mr. Shintaro Nakatasuka Manager Certification Business Dept. II Mazda Motor Corporation P.O. Box 18 Hiroshima 703 91 JAPAN; Dear Mr. Nakatasuka: This responds to your letter requesting an interpretation of Part 541 *Federal Motor Vehicle Theft Prevention Standard*. You asked two separate questions, which are discussed in detail below.; First, you stated that you plan to introduce a 1987 carline in Februar 1986. This particular carline has been selected as one that will be subject to the requirements of Part 541. However, Part 541 does not become effective until April 24, 1986. You stated your belief that the introduction of the 1987 vehicles before the effective date of Part 541 means that none of the 1987 vehicles in that carline will be required to comply with Part 541. Your belief is a correct interpretation. Nevertheless, you stated that Mazda would voluntarily comply with the requirements of Part 541 for the 1987 vehicles in that carline produced after April 24, 1986, the effective date for Part 541. You asked whether your voluntary marking of some of the 1987 vehicles in that carline would cause this agency to conclude that *all* of the 1987 vehicles in that carline were not in compliance with Part 541. It will not.; As you noted, the effective date for Part 541 is April 24, 1986. Thi effective date means that Part 541 applies to all selected carlines beginning with the 1987 model year. However, the legislative history for Title VI of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 2021 *et seq*.), which Title requires that Part 541 be promulgated, expressly states: 'The theft prevention standard cannot apply to a car in the middle of the model year.' H.R. Rep. No. 1087, 98th Cong., 2d Sess. at 11 (1984).; For purposes of Title VI of the Cost Savings Act, NHTSA believes tha the model year for a carline begins on the day on which a vehicle in that carline is introduced into commerce in the United States. Hence, if a 1987 model year vehicle in a carline is introduced into commerce before the effective date of Part 541, the 1987 model year for that carline would have begun prior to the effective date of the theft prevention standard. Obviously, the requirements of a standard do not apply before the effective date. Given the clear expression of Congressional intent that this theft prevention standard cannot apply to a carline in the middle of its model year, NHTSA concludes that a 1987 model year version of a carline introduced into commerce before the effective date of the theft prevention standard is not subject to the requirements of the theft prevention standard for the 1987 model year. It would, of course, be subject to the requirements for the 1988 model year.; Having concluded that the theft prevention standard does not apply t such 1987 model year vehicles, any voluntary actions taken by the vehicle manufacturer cannot affect this conclusion. Your company may choose to mark the 1987 vehicles in this carline introduced on or after the effective date of Part 541, as your letter indicates you plan to do. On the other hand, you may choose not to mark those or any of the 1987 vehicles in this carline. Whichever course of action you choose does not change the fact that Part 541 does not apply to the 1987 model year vehicles of a carline introduced into commerce before April 24, 1986.; Second, you stated that Part 541 was unclear as to whether a metal ta stamped with the vehicle identification number and affixed to a vehicle part by mans of 'one-way screws' would be considered 'labels', subject to the requirements of section 541.5(d)(1), or 'other means of identification', subject to the requirements of section 541.5(d)(2). All means of identification which are affixed to a part are considered labels for purposes of Part 541.; Section 541.5 expressly states that the required markings 'must b *affixed* by means that comply with paragraph (d)(1) of this section or *inscribed* by means that comply with paragraph (d)(2) of this section' (Emphasis added). All markings which are affixed to a part, whether by means of adhesive, one- way screws, rivets, or welding, are labels. As such, those markings must satisfy all the requirements of section 541.5(d)(1). Conversely, all markings which are inscribed into a part, whether by means of etching, stamping, engraving, or sandblasting, are other means of identification. As such, those markings must satisfy all the requirements of section 541.5(d)(2).; If you have any further questions or need more information on thi subject, please do not hesitate to contact me.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0026OpenMr. Henri B. Combe, Executive Vice President, Peugeot, Inc., 107-40 Queens Boulevard, Forest Hills, NY, 11375; Mr. Henri B. Combe Executive Vice President Peugeot Inc. 107-40 Queens Boulevard Forest Hills NY 11375; Dear Mr. Combe: In answer to your letter of May 26, concerning Federal Motor Vehicl Safety Standards Nos. 208 and 210, your interpretation is correct: a four-passenger automobile (such as the Peugeot 404) must have two Type 2 seat belt assemblies for the front seat passengers if the windshield header is within the head impact area, two Type 1 or Type 2 seat belt assemblies for the front seat passengers if the windshield header is not within the head impact area, and two Type 1 seat belt assemblies for the rear seat passengers. However anchorages for Type 2 seat belt assemblies are required in the rear to enable the owner to install Type 2 seat belt assemblies should he desire to afford his rear seat passengers this means of protection.; Sincerely yours, Robert M. O Mahoney, Assistant General Counsel |
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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.