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: aiam2671OpenMr. Ray Sizemore, Crane Carrier Company, 1925 N. Sheridan, P.O. Box 51191, Tulsa, OK 74151; Mr. Ray Sizemore Crane Carrier Company 1925 N. Sheridan P.O. Box 51191 Tulsa OK 74151; Dear Mr. Sizemore: This responds to Crane Carrier Corporation's June 8, 1977, questio whether the maximum time limits specified by S5.1.1 of Standard No. 121, *Air Brake Systems*, for build-up of brake system air pressure from 85 to 100 psi includes the time taken to build up air pressure in an accessory reservoir (for an air starter) that is replenished only when the truck is started.; The answer to your question is no. Section S5.1.1 is a performanc requirement that assures that repeated use of the brakes during vehicle operation will not deplete the available air supply because of insufficient air compressor capacity. The purpose of this requirement only indirectly relates to the initial air pressure build-up that occurs when the vehicle is first started.; The agency's existing laboratory procedure for compliance testin provides for fully charging the air brake system (and any accessory reservoirs which charge automatically in the process) before the test is begun. The engine is shut off while brake system air pressure is reduced to a level that permits a subsequent build-up for measurement purposes. In order to properly test vehicles with air starters, the agency is modifying its procedure to keep the engine running throughout the test, so that the air starter reservoir remains fully charged throughout the measurement period.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
ID: aiam3963OpenMr. Don Benfield, Sales Manager, Express Yourself Company', P.O. Box 2357, Anderson, IN 46018; Mr. Don Benfield Sales Manager Express Yourself Company' P.O. Box 2357 Anderson IN 46018; Dear Mr. Benfield: Thank you for your letter of April 12, 1985, concerning stat regulations that might affect a product you are considering. You explained that your product would fit inside the rear window of a vehicle. While we do not have information on state laws, I can explain the possible effect of Federal law on your potential product. I suggest you contact vehicle safety officials in the states in which you plan to sell your product to learn of their laws.; The National Traffic and Motor Vehicle Safety Act authorizes our agenc to issue Federal Motor Vehicle Safety Standards that apply to new motor vehicles and items of motor vehicle equipment. The agency has issued Federal Motor Safety Standard No. 205, *Glazing Materials*, which sets performance requirements for glazing materials used in new motor vehicles and glazing materials sold as items of replacement equipment, a copy of the standard is enclosed. If your product is mounted on, rather than inside, the rear window, it could be affected by Standard No. 205.; The performance requirements of the standard include ones regulatin the light transmittance and abrasion resistance of glazing. Manufacturers of new vehicles must certify that the glazing in windows requisite for driving visibility conforms with the light transmittance and other requirements of the standard. If a manufacturer or dealer places your product on the rear window in a new vehicle prior to the sale of the vehicle, that person must certify that the glazing continues to be in compliance with the requirements of Standard No. 205.; In 1974, Congress amended the National Traffic and Motor Vehicle Safet Act to address the problems of persons tampering with safety equipment installed on a motor vehicle by adding section 108(a)(2)(A) to the Act. That section provides, in part, that:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor safety standard....<<<; Thus no manufacturer, distributor, dealer, or motor vehicle repai business may add material to the glazing materials of a motor vehicle, if that material would render inoperative the glazing's compliance with Standard No. 205.; Section 108(a)(2)(A) does not establish any limitations on a individual vehicle owner's ability to alter his or her own vehicle. Under Federal law, individual vehicle owners can themselves install any material they want on their vehicles, regardless of whether that material would render inoperative the compliance of the vehicle's glazing with the performance requirements of Standard No. 205.; If your product is not mounted on the window itself, it still may b affected by our standards. Standard No. 111, *Rearview Mirrors*, sets performance requirements for rearview mirrors, a copy of the standard is enclosed. The standard provides that each inside rearview mirror must provide a specified field of view to the rear of the vehicle. If the field of view of the inside mirror in a new vehicle is obstructed by anything other than head restraints or seated occupants, then an outside rearview mirror must be provided on the passenger's side of the vehicle.; Thus, if your product were mounted inside the rear window of a ne vehicle by a manufacturer or dealer at the time of its sale, and if installation of your product would mean that the inside rearview mirror would no longer comply with the applicable field of view requirements, they would have to ensure the vehicle was equipped with the necessary additional mirror required by Standard 111. Just as with Standard No. 205, section 108(a)(2)(A) would apply to the installation of your product in used vehicles by manufacturers, distributors, dealers, and motor vehicle repair shops. Thus, if your product is mounted inside the rear window and its installation would mean that the inside rearview mirror would no longer comply with the applicable field of view requirements, an outside passenger side mirror would have to be installed. Again, section 108(a)(2)(A) does not limit the actions of individual vehicle owners.; If you have further questions, please let me know. Sincerely, Jeffrey R. Miller, Chief Counsel |
|
ID: aiam3349OpenMr. William Blythe, 1545 University Avenue, Palo Alto, CA 94301; Mr. William Blythe 1545 University Avenue Palo Alto CA 94301; Dear Mr. Blythe: This responds to your recent letter asking questions concerning th test procedures of Safety Standard No. 216, *Roof Crush Resistance* (49 CFR 571.216). Specifically, you are concerned with the proper applications of the test block forces specified in paragraphs S6.3 and S6.2(d) of the standard.; Your first question asks whether paragraph S6.3 allows the force on th test block to be applied 'essentially opposite the initial contact point of the roof to the block.' Paragraph S6.3 specifies that the force required by the standard shall be applied in a downward direction to the lower surface of the test device. Figure 1 of the standard illustrates this procedure and indicates that the force is to be centrally applied to the loading block. This procedure will be followed during tests by the agency to determine the compliance of particular passenger cars with Safety Standard No. 216. Therefore, we would not recommend that you apply the force opposite the initial contact point of the test block with the roof.; Paragraph S6.2(d) of the standard specifies that the initial contac point (with the roof) is on the longitudinal centerline of the lower surface of the test device and 10 inches from the forwardmost point of the centerline. Your second question asks whether this 10-inch dimension should be maintained if this places the leading edge of the test device behind the leading edge of the roof and the A-pillars. You state that this would occur with certain roof configurations which tend to be high in the center (i.e., in which the leading edge of the roof is not the highest point of the roof). A manufacturer should adhere to the 10-inch dimension even if this means the leading edge of the test device will not be forward of the A-pillar and the roof's forward edge. The test procedures specified are standardized procedures which the agency applies to all passenger cars regardless of roof configuration. Thus, the agency would maintain the 10-inch dimension even when testing a roof with a higher center than its leading edge.; I would like to point out, however, that the test procedures specifie in the safety standards only document how the agency will conduct its compliance tests. Manufacturers are not required to test vehicles according to the procedures specified. A manufacturer's responsibility is to exercise due care to ascertain that its vehicles are in fact in compliance with the standards (15 U.S.C. 1397). If you are convinced that the procedures mentioned in your letter would accurately test the compliance of a particular vehicle with Safety Standard No. 216, you are certainly permitted to use those procedures. It is up to the manufacturer, however, to determine whether it has in fact exercised due care to determine compliance.; I hope this has been responsive to your inquiry. Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam4028OpenMr. D. F. Landers, President, The London Coach Co., Inc., 25 Eldredge, P.O. Box 1183, Mt. Clemens, MI 48043; Mr. D. F. Landers President The London Coach Co. Inc. 25 Eldredge P.O. Box 1183 Mt. Clemens MI 48043; Dear Mr. Landers: This responds to your June 6, 1985 letter concerning Federal Moto Vehicle Safety Standard No. 207, *Seating Systems*. We apologize for the delay in our response. You asked whether your vehicle's 'folding flip seats' are required by section S4.3 of the standard to be equipped with a restraining device. As discussed below, the answer is no.; By the (sic) way of background information, this agency does no provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with applicable safety standards. The following represents our opinion based on the facts provided in your letter.; Section S4.3 of Standard No. 207 states: >>>...a hinged or folding *occupant seat* or occupant seat back shal be equipped with a self-locking device for restraining the hinged or folding seat or seat back and control for releasing that restraining device. (Emphasis added.)<<<; The term 'occupant seat' is defined in section S3 of Standard No. 20 as, 'a seat that provides at least one designated seating position.' The term 'designated seating position' is defined in 49 CFR Part 571.3(b) as:; >>>any plan view location capable of accommodating a person at least a large as a 5th percentile adult female, if the overall seat configuration and design is such that the position is likely to be used as a seating position while the vehicle is in motion, *except for the auxiliary seating accommodations such as temporary or folding jump seats.... (Emphasis added.)<<<; The issue raised by your letter is whether your folding flip seats ar seats that provide a designated seating position, within the definition of 49 CFR Part 571.3(b). If a seat provides a designated seating position, it is an occupant seat under Standard No. 207 and subject to section S4.3's requirement for a restraining device.; It is our opinion that your folding flip seats are 'auxiliary seatin accomodations (sic)' and therefore not subject to the Standard No. 207's requirement for a restraining device. This conclusion is based on the information shown on your brochure. The brochure shows that each of the flip seats normally remains folded up. When they are temporarily needed to accommodate additional passengers, they can be folded down to form a seating surface.; While folding jump seats are not subject to a number of safet requirements, including those of Standards No. 207 and 208, *Occupant Crash Protection*, we encourage you to ensure that the seats provide safe performance when in use. In particular, we would encourage you to provide safety belts for these seats to ensure that their occupants will have adequate crash protection.; Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam3217OpenThomas G. Richards, SAFECO, SAFECO Plaza, Seattle, WA 98185; Thomas G. Richards SAFECO SAFECO Plaza Seattle WA 98185; Dear Mr. Richards: This is in response to your letter of February 29, 1980, requestin information on the Federal odometer disclosure requirements. The question you raised is whether odometer disclosure statements have to be executed and retained when the vehicle involved in a purchase and sale is a salvage vehicle.; If the vehicle is repairable and will subsequently be used as a moto vehicle, disclosure must be made. However, if the vehicle is so badly damaged that it cannot be returned to the road, it will have ceased to be a motor vehicle for purposes of the odometer regulations (49 CFR Part 580). Disclosure would therefore not be required. You must keep in mind that this is a judgement that will have to be made in good faith by the seller of the vehicle.; Sincerely, John Womack, Assistant Chief Counsel |
|
ID: aiam1380OpenHonorable Charles H. Percy, United States Senate, Washington, DC 20015; Honorable Charles H. Percy United States Senate Washington DC 20015; Dear Senator Percy: This is in reply to your communication of January 3, 1974, forwardin to us correspondence dated November 29, 1973, from Mr. Bruce Motyka of Des Plaines. Mr. Motyka requests information regarding laws relating to pickup truck and camper weight limits, laws or studies relating to the sale of trucks exceeding GVW (Gross Vehicle Weight) rate minimums, and regulations or studies regarding maximum weights for tires.; The NHTSA has issued regulations relating to the installation o campers onto pickup trucks. Motor Vehicle Safety Standard No. 126 'Truck camper loading' (49 CFR S 571.126) requires each camper to bear a permanent label containing information on its maximum loaded weight. The standard also requires each camper to be furnished with an owner's manual that contains information on total camper weight, the selection of an appropriate pickup truck, appropriate methods of camper loading, how to determine the camper's center of gravity and where it should be placed in the truck cargo area. A companion 'Consumer Information' regulation, 'Truck camper loading' (49 CFR S 575.103) requires that written information be provided at the sale of each truck capable of being equipped with a slide-in camper that deals with the correct installation of a slide-in camper in that vehicle. This information is also required to be available in dealers' showrooms for retention by prospective purchasers of such trucks.; Other NHTSA regulations (49 CFR Part 567, 'Certification') requir every motor vehicle, including pickup trucks, to be labeled, usually on the driver's door or door jam, with its gross vehicle weight rating, and the gross axle weight rating for each axle. Each of these ratings is intended to be based on the weight of a fully loaded vehicle, as determined by the vehicle's manufacturer. While it is possible for manufacturers proposed course of action appears to have the aim of generating dissatisfaction with Federal tire regulations among dealers and distributors, and could, by lessening cooperation at the retail level, interfere with your client's ability to fulfill its obligations under the regulations.; Sincerely, Frank Berndt, Acting Chief Counsel |
|
ID: aiam4478OpenMr. Al Cunningham Chief Engineer Wesbar Corporation P.O. Box 577 West Bend, WI 53095; Mr. Al Cunningham Chief Engineer Wesbar Corporation P.O. Box 577 West Bend WI 53095; Dear Mr. Cunningham: This is in reply to your letter of September l4 l988, attaching two lamps, and asking for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to each. Specifically, you wish clarifications of SAE J588e, 'the definition...2.2 'Multiple Compartment Lamp' and the term used in 3.1 'Single Compartment Lamp''. SAE Standard J588e Turn Signal Lamps, incorporated by reference in Standard No. 108, defines a multiple compartment lamp as 'a device which gives its indication by two or more separately lighted areas which are joined by one or more common parts such as a housing or lens.' The term 'single compartment lamp' is not used in section 3.1, though the term 'single compartment photometric requirements' is used in referencing the values for one 'lighted section' given in Table 1 of J588e. For purposes of this discussion we shall define a 'single compartment lamp' as one that gives its indication by one lighted area. You have described your first lamp as 'a housing with back and four sides containing a two filament bulb with a single lens covering face of housing.' The lamp photometrically complies to the basic requirements of a Class A tail, stop and turn signal lamp. You have asked if this lamp is a single compartment lamp. The answer is yes, your model 3504 Exp. contains a single light source and has a single lighted area. Your second lamp is described as 'a housing with a back, two sides and one end, containing one; 57 bulb and one 1157 (2 filament) bulb. This housing is closed with two red lenses, on on the end and one on the face with an additional clear lens on bottom side. This lamp also complies to all standards of a class A tail, stop and turn lamp plus side marker clearance, license plate illuminator and class a reflex reflector side and rear'. You ask if this also is a single compartment lamp. The answer is yes. The term 'separately lighted area' in the definition of a multiple compartment lamp is understood to mean an area that is illuminated by a separate light source. In your model 3504 the turn signal light is provided by the; 1157 bulb alone, and not in tandem with the 57 bulb. I hope that this provides the clarification you seek. We ar returning your lamps under separate cover. Sincerely, Erika Z. Jones Chief Counsel; |
|
ID: aiam4182OpenMr. T. Chikada, Manager, Automotive Lighting, Engineering Control Dept., Stanley Electric Co. Ltd., 2-9-13, Nakameguro-ku, Tokyo 153, Japan; Mr. T. Chikada Manager Automotive Lighting Engineering Control Dept. Stanley Electric Co. Ltd. 2-9-13 Nakameguro-ku Tokyo 153 Japan; Dear Mr. Chikada: This is in reply to your letter of July 7, 1986, asking for our advic on a decorative lighting device for motorcycles. The general principle remains the same as when I last explained it to you. Please refer to my letter to you dated March 24, 1986 (copy enclosed) on the relationship of paragraph S4.1.3 of Motor Vehicle Safety Standard No. 108 to auxiliary lighting devices for motorcycles. If you conclude that the device would not impair the lighting equipment required by Standard No. 108 then paragraph S4.1.3 would not prohibit your device.; You may follow this guideline with reference to any future question you may have about the permissibility of auxiliary motor vehicle lighting devices. The agency does not approve or disapprove of specific items of lighting equipment.; Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam3647OpenMr. H. Nakaya, Mazda (North America), Inc., 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. Nakaya Mazda (North America) Inc. 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Nakaya: This responds to your letter asking about the definition of occupan compartment air space for purposes of determining the application of Standard No. 302, *Flammability of Interior Materials*. You asked whether the cargo areas of two cars must comply with the standard if these areas always or sometimes open into the occupant compartment.; The term 'occupant compartment air space' is defined in the standard a 'the space within the occupant compartment that normally contains refreshable air.' In previous interpretations regarding the applicability of the standard to a particular area of a vehicle, the question has turned upon whether people can and do ride in the area in question. In letters regarding vans, the agency has taken the position that the space to the rear of the rearmost seat was not part of the occupant compartment. The reasoning underlying those interpretations was that that area was not typically occupied by passengers. However, the agency came to a different conclusion regarding the space behind the rear seat in station wagons. Since passengers can and do ride in that area, the agency concluded that it was part of the occupant compartment. For this interpretation, see the last page of the enclosed letter.; The Case I car in your letter presents a situation seemingly similar t that of station wagons. The Case I car appears to be a liftback car with a cargo carrying area behind the rear seat. If passengers can ride in the area behind the rear seat, then that area would be part of the occupant compartment and would be subject to the standard. As to the Case II car, which appears to be a sedan with internal access to the trunk by means of the folding backs of the rear seats, the agency does not regard the trunk area as part of the occupant compartment. It does not appear from your diagrams that people would ride in that area.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam2955OpenMr. William J. Baldridge, City Manager, City of Royal Oak, P.O. Box 64, Royal Oak, MI 48068; Mr. William J. Baldridge City Manager City of Royal Oak P.O. Box 64 Royal Oak MI 48068; Dear Mr. Baldridge: This responds to your December 21, 1978, letter asking the Nationa Highway Traffic Safety Administration (NHTSA) to permit the City of Royal Oak, Michigan to obtain a waiver from the safety standards applicable to one of its vehicles. In particular, you ask that several standards be waived because the vehicle, as altered by the addition of an aerial bucket, would no longer comply with them.; Your letter does not clearly indicate the cause of the noncomplianc with Federal safety standards. The NHTSA concludes that the noncompliance probably arises because the altered vehicle will exceed the 'unloaded vehicle weight' that is used in determining its compliance with several of the agency's standards. Although the agency appreciates the problems that your city has with obtaining a complying vehicle, the NHTSA has no authority to grant exemptions from safety standards for individual vehicle *users*.; The manufacturer and alterer of the vehicle are responsible fo certifying that it complies with all Federal safety standards. The Federal government does not issue certificates that any vehicle complies with safety standards. The manufacturer or alterer, as part of its certification, must insure that its vehicle does not exceed the weight restrictions that are appropriate for the vehicle. Accordingly, if a vehicle alterer has informed you that an alteration cannot be done without exceeding the manufacturer's established weight restrictions, then the alterer could not truthfully certify the vehicle for compliance.; The NHTSA regrets the problems caused to Royal Oak by th implementation of the safety standards. The agency has received a petition from the Truck Body and Equipment Association asking for rulemaking to prevent future problems such as yours. The NHTSA currently is evaluating that petition. To resolve your problem, the agency suggests that you consider selling the chassis and utility body that you currently own and purchase another chassis and body that has a sufficient 'unloaded vehicle weight' to accommodate the alteration you intend. This will enable the vehicle that you finally obtain to comply with safety standards. These standards improve vehicle safety, and we are sure that Royal Oak would not want to purchase an unsafe vehicle.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
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.