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
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ID: aiam4707OpenMr. T. Chikada Manager, Automotive Lighting Engineering Control Dept. Stanley Electric Co., Ltd. 2-9-13, Nakameguro, Meguro-ku Tokyo 153, Japan; Mr. T. Chikada Manager Automotive Lighting Engineering Control Dept. Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Mr. Chikada: This is in reply to your letter with respect to tw types of decorative lighting devices intended for installation 'on the rear face, and at the top of optional motorcycle rear trunks respectively.' I regret the delay in responding. Type A and Type B would be installed on the same motorcycle. Type A would be installed at the top of the trunk. It consists of an elongated device, illuminated by LEDs when the taillamp is on. Type B is installed on the motorcycle itself. It is a rectangular device, illuminated by an incandescent bulb, which is mounted on the vertical centerline and is flanked by the tail and stop lamps. The distance between the center of the light sources on the two devices is 290mm. (approximately ll 1/2 inches). Both devices emit red light, and their maximum intensity is less than the minimum intensity of the taillamp. You have asked whether it is permitted to equip a motorcycle with the Type A and Type B accessory lamps. If the answer is affirmative, you have asked whether an LED could be used as the light source for Type B. You have also asked whether the maximum intensity of each device separately should be less than the minimum intensity of the tail lamp, or whether the combined maximum intensity of both devices should be less than the minimum intensity of the tail lamp. Paragraph S5.1.3 of Federal Motor Vehicle Safety Standard No. 108 (formerly S4.1.3) permits the installation of these lamps if they do not impair the effectiveness of the lighting equipment required by the standard. In this instance, the question to be asked is whether the devices, activated with the taillamps, impair the effectiveness of the taillamps, or the stop lamps. The devices are, in effect, supplemental taillamps, and as such, arguably do not appear to impair the effectiveness of the taillamps required by the standard no matter what their intensity is. The diagram of Type B indicates that the stop lamps and taillamps are in the same compartment, presumably incorporating a dual filament bulb. Although the stop lamps when activated are brighter than the taillamps, their proximity to the supplemental devices Type A and Type B, each of which are emitting a red light, leads to the possibility that the stop signal would not be as effective as it would be were there no other red lights in the vicinity, and hence impaired within the meaning of S5.1.3. A stop signal must be instantly perceived so that a following driver may determine appropriate action to take. However, we note that this configuration is similar to other stop/taillamp configurations on many vehicles in use on the highways. This would indicate that such configurations do not result in impairment. Thus, the answer to your first question is that both Types of devices are permitted under the standard. Your second question is whether LEDs are acceptable light sources for Type B. Since there is no restriction on light sources for a lighting device not required by Standard No. 108, you may use the LEDs as light sources. Your third question is whether the maximum intensity of Type A and Type B, separately, should be less than the minimum intensity of the taillamp. Even though Type A and Type B are optional devices, in the configuration depicted where Type B is immediately flanked on both sides by a taillamp, the appearance of the three lamps would be that of a multicompartment lamp, even though they may actually be separate. To help assure that impairment of either the taillamp or stop lamp does not occur, the intensity of Type B should be identical with that of the taillamps. Otherwise, observers may assume that Type B (which you intend to have an intensity less than a taillamp) is actually the taillamp, and the actual taillamps (which you intend to have an intensity greater than Type B) might appear to be stop lamps that are continually on. This would be deemed impairment since there would be three intensity levels, increasing the possibility of confusion of the intent of the lamps. As for Type A, its vertical separation decreases the possibility for confusion. If the light sources are LEDs, the color would be a different shade of red that the stop and taillamps. Thus, the intensity is less important. However, it functions as an auxiliary taillamp and should be within the same intensity range as the original equipment taillamps. Finally, you asked whether the combined maximum intensity of both devices would be less than the minimum intensity of the taillamps. Again, this would create three levels of intensity, and could cause confusion in understanding the intent of the lamps. As noted above, the individual intensities should be similar to the intensity of the taillamps. I hope that this answers your questions. Sincerely, Stephen P. Wood Acting Chief Counsel; |
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ID: aiam3889OpenMr. Nick Martz, Regional Sales Manager, Isuzu Diesel of North America, 41169 Vincenti Court, Novi, MI 48050; Mr. Nick Martz Regional Sales Manager Isuzu Diesel of North America 41169 Vincenti Court Novi MI 48050; Dear Mr. Martz: This responds to your letter asking about identification requirement applicable to water temperature, oil pressure and alternator instruments on bread delivery trucks. You asked whether the symbols specified by Standard No. 101, *Controls and Displays*, are required for such trucks and, if so, whether it is permissible to use transparent decals with the proper symbols on the lenses. You also asked whether waivers can be issued. The answers to your questions are provided below.; Federal Motor Vehicle Safety Standard No. 101, *Controls and Displays* specifies requirements for the location, identification, and illumination of motor vehicle controls and displays. Water temperature, oil pressure and alternator instruments are displays. While the standard's requirements for controls apply to all trucks, the standard's requirements for displays are only applicable to trucks with a gross vehicles weight rating of less than 10,000 pounds. See section S5.; Assuming that your bread trucks do have a gross vehicle weight ratin of less than 10,000 pounds, the instruments must be identified by the symbols specified by Standard No. 101. Section S.2.3 provides in relevant part:; >>>Except for informational readout displays, any display locate within the passenger compartment and listed in column 1 of Table 2 that has a symbol designated in column 4, shall be identified by that symbol. Such display may, in addition be identified by the word or abbreviation shown in column 3.... Additional words or symbols may be used at the manufacturer's discretion for the purpose of clarity. The identification required or permitted by this section shall be placed on or adjacent to the display that it identifies. The identification of any display shall, under the conditions of S6, be visible to the driver and appear to the driver perceptually upright.<<<; The displays described by your letter are conventional gauges rathe than informational readout displays. (Informational readout displays are defined by the standard to be displays using light-emitting diodes, liquid crystals, or other elector illuminating devices where one or more than one type of information may be displayed.) Table 2 specifies symbols for, among other displays, oil pressure gauges, coolant temperature gauges, and electrical charge gauges. Therefore, under S5.2.3, the displays must be identified by the specified symbols.; Standard No. 101 does not specify the nature of the material to be use in identifying displays, i.e., paint, decals, etc. Therefore, it is permissible to use decals.; You also asked whether waivers can be issued. In a telephon conversation with Edward Glancy of this office, you indicated that some trucks have been produced using words rather than symbols to identify the gauges discussed above. 49 CFR Part 556 sets forth procedures for petitioning for exemption from the notification and remedy requirements of the National Traffic and Motor Vehicle Safety Act due to the inconsequentiality of a noncompliance with a safety standard as it relates to motor vehicle safety. I have enclosed a copy of Part 556 for you convenience, as well as a copy of Standard No. 101.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2476OpenMr. W. Bailey Watson, P. O. Box 4307, North Charleston, SC 29405; Mr. W. Bailey Watson P. O. Box 4307 North Charleston SC 29405; Dear Mr. Watson: Your letter of August 16, 1976, asking whether the 1972 Pontia Bonneville was equipped with a safety bumper has been forwarded to this office by the Federal Trade Commission for reply.; The National Highway Traffic Safety Administration (NHTSA), which i responsible for developing motor vehicle safety standards, promulgated Standard No. 215, *Exterior Protection*, to protect certain safety components when a vehicle is involved in low-speed front and rear collisions. The standard, in its initial form, became effective on September 1, 1972, and provided that passenger cars be capable of sustaining 5 mph front and 2 1/2 mph rear barrier impacts with no damage resulting to lighting, cooling, fuel, or exhaust systems, or to doors and other closures. In order to comply with the required performance level, manufacturers had to strengthen their vehicle bumper systems.; The standard only affects cars manufactured after September 1, 1972 and the start of the 1973 model year. It is therefore unlikely that any 1972 model vehicles would have been produced under its authority. Before September 1, 1972, the Federal government imposed no safety requirements affecting motor vehicle bumpers. Thus, vehicle manufacturers were free to equip their automobiles with any type of bumpers they chose. The NHTSA cannot comment on the safety qualities of the 1972 Pontiac Bonneville bumper since it was not at that time involved in regulating that aspect of vehicle performance.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5547OpenMr. Dietmar K. Haenchen Manager, Vehicle Regulations Volkswagen of America, Inc. 3800 Hamlin Road Auburn Hills, MI 48326; Mr. Dietmar K. Haenchen Manager Vehicle Regulations Volkswagen of America Inc. 3800 Hamlin Road Auburn Hills MI 48326; "Dear Mr. Haenchen: This responds to your request for an interpretatio of Standard No. 118, Power- operated window, partition, and roof panel systems. You asked whether the 'squeezing force limitation' of S5 applies only to the first attempt to close a power operated window, partition, or roof panel system (power-operated system) and not to immediately following attempts to close. You explained that an operator may initiate more than one closing attempt in order to assure the closing of the power operated system under adverse conditions such as low temperature or the presence of ice in the power operated system's track. As discussed below, the S5 squeezing force limitation applies to each closing attempt. By way of background information, Standard No. 118 requires that a power operated system, while closing, must comply with one of two alternative provisions. The first, S4, generally specifies requirements for situations where a person is expected to be in the immediate vicinity of the vehicle to supervise the closing. The second, S5, covers 'unsupervised' closings, i.e., automatic closings or closings where the person initiating the closing is further away from the vehicle. In the rulemaking establishing S5, NHTSA recognized that unsupervised closings increase the risk that persons, especially children, could be caught between a closing system and the frame. Therefore, to the extent that a power operated system permits unsupervised closings, the agency decided to require an automatic reversal mechanism that reverses the window direction upon its meeting an obstruction. More specifically, if an obstruction is between 4 and 200 mm from any part of the vehicle structure with which the closing system mates, S5 requires window reversal before a force of 100 Newtons is encountered. S5 does not specify different squeezing force limitation requirements for different closing attempts. Therefore, a power operated system must meet the same requirements for each closing attempt. We note that since the requirements of S5 address unsupervised closings, the same safety concerns about children being caught between a closing system and frame would be relevant to each closing attempt. I note that NHTSA decided not to apply the S5 squeezing force limitation requirement to unsupervised closings within the area between 4 mm and any part of the vehicle structure with which the closing system mates. The agency recognized that injury from system closure is not possible in this area, and that unnecessary automatic reversal could result from the system's misalignment or obstruction from ice. Thus, during unsupervised closing, if the system encounters an obstruction less than 4 mm from any part of the vehicle structure with which the closing system mates, the power operated system need not reverse. I hope that this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam5546OpenMr. Dietmar K. Haenchen Manager, Vehicle Regulations Volkswagen of America, Inc. 3800 Hamlin Road Auburn Hills, MI 48326; Mr. Dietmar K. Haenchen Manager Vehicle Regulations Volkswagen of America Inc. 3800 Hamlin Road Auburn Hills MI 48326; "Dear Mr. Haenchen: This responds to your request for an interpretatio of Standard No. 118, Power- operated window, partition, and roof panel systems. You asked whether the 'squeezing force limitation' of S5 applies only to the first attempt to close a power operated window, partition, or roof panel system (power-operated system) and not to immediately following attempts to close. You explained that an operator may initiate more than one closing attempt in order to assure the closing of the power operated system under adverse conditions such as low temperature or the presence of ice in the power operated system's track. As discussed below, the S5 squeezing force limitation applies to each closing attempt. By way of background information, Standard No. 118 requires that a power operated system, while closing, must comply with one of two alternative provisions. The first, S4, generally specifies requirements for situations where a person is expected to be in the immediate vicinity of the vehicle to supervise the closing. The second, S5, covers 'unsupervised' closings, i.e., automatic closings or closings where the person initiating the closing is further away from the vehicle. In the rulemaking establishing S5, NHTSA recognized that unsupervised closings increase the risk that persons, especially children, could be caught between a closing system and the frame. Therefore, to the extent that a power operated system permits unsupervised closings, the agency decided to require an automatic reversal mechanism that reverses the window direction upon its meeting an obstruction. More specifically, if an obstruction is between 4 and 200 mm from any part of the vehicle structure with which the closing system mates, S5 requires window reversal before a force of 100 Newtons is encountered. S5 does not specify different squeezing force limitation requirements for different closing attempts. Therefore, a power operated system must meet the same requirements for each closing attempt. We note that since the requirements of S5 address unsupervised closings, the same safety concerns about children being caught between a closing system and frame would be relevant to each closing attempt. I note that NHTSA decided not to apply the S5 squeezing force limitation requirement to unsupervised closings within the area between 4 mm and any part of the vehicle structure with which the closing system mates. The agency recognized that injury from system closure is not possible in this area, and that unnecessary automatic reversal could result from the system's misalignment or obstruction from ice. Thus, during unsupervised closing, if the system encounters an obstruction less than 4 mm from any part of the vehicle structure with which the closing system mates, the power operated system need not reverse. I hope that this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0163OpenGeorge M. Hilgendorf, Esq., One North La Salle Street, Suite 4100, Chicago, Illinois 60602; George M. Hilgendorf Esq. One North La Salle Street Suite 4100 Chicago Illinois 60602; Dear Mr. Hilgendorf: Mr. Frank Coy, Special Assistant to the Under Secretary o Transportation, has asked that I respond to your letter of April 16, 1969, in which you ask whether a station wagon purchased in March of 1968, equipped with two ply tires, violates Federal Motor Vehicle Safety Standard No. 109.; The vehicle you purchased was apparently manufactured prior to April 1 1968, and therefore, it was not required to be equipped with tires conforming to Standard No. 109. However, even if the standard were applicable, because a tire is labeled '2-ply' it is not necessarily a non-conforming tire. Standard No. 109 does not specifically require tires to have a given number of plies. It does require that irrespective of any ply rating tires pass minimum performance tests. As to passenger cars, Standard No. 110 requires that passenger car manufactured after April 1, 1968, (1) must be equipped with tires that comply with Standard No. 109, and (2) the vehicle must not place a load on any of the tires greater than the load capacity of the tire specified in Standard No. 109.; Very truly yours, Howard A. Heffron, Chief Counsel |
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ID: aiam0162OpenGeorge M. Hilgendorf, Esq., One North La Salle Street, Suite 400, Chicago, Illinois 60602; George M. Hilgendorf Esq. One North La Salle Street Suite 400 Chicago Illinois 60602; Dear Mr. Hilgendorf: Mr. Frank Coy, Special Assistant to the Under Secretary o Transportation has asked that I respond to your letter of April 16, 1969, in which you ask whether a station wagon purchased in March of 1968, equipped with two ply tires, violates Federal Motor Vehicle Safety Standard No. 109.; The vehicle you purchased was apparently manufactured prior to April 1 1968, and therefore, it was not required to be equipped with tires conforming to Standard No. 109. However, even if the standards were applicable, because a tire is labeled '2-ply' it is not necessarily a non-conforming tire. Standard No. 109 does not specifically require tires to have a given number of plies. It does require that irrespective of any ply rating tires pass minimum performance tests. As to passenger cars, Standard No. 110 requires that passenger cars manufactured after April 1, 1968, (1) must be equipped with tires that comply with Standard No. 109, and (2) the vehicle must not place a load on any of the tires greater than the load capacity of the tire specified in Standard No. 109.; Very truly yours, Howard A. Heffron, Chief Counsel |
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ID: aiam3378OpenD. G. McGuigan, Esq., Office of the General Counsel, Ford Motor Company, The American Road, Dearborn, MI 48121; D. G. McGuigan Esq. Office of the General Counsel Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. McGuigan: This responds to your letter of November 10, 1980, concerning Standar No. 213, *Child Restraint Systems*. You asked whether Ford may make a minor variation in the language specified in S5.5.2(g) for the label that must be permanently affixed to child restraints. As explained below, you may use the language proposed in your letter.; Section 5.5.1 of the standard requires that each child restraint b permanently labeled with specified information. Section 5.5.3 requires that the information specified in S5.5.2(g)-(k) must be displayed on the child restraint so that it is visible when the restraint is installed in the vehicle.; You state that the only information specified for the visible labe that is applicable to the Ford 'TOT GUARD' is the language in S5.5.2(g). That section provides that the child restraint must be labeled with the following words:; >>>WARNING! FAILURE TO FOLLOW EACH OF THE FOLLOWING INSTRUCTIONS CA RESULT IN YOUR CHILD STRIKING THE VEHICLE'S INTERIOR DURING A SUDDEN STOP OR CRASH:; SECURE THIS CHILD RESTRAINT WITH A VEHICLE BELT AS SPECIFIED IN TH MANUFACTURER'S INSTRUCTIONS LOCATED________________.<<<; You are concerned that the above language may create potentia confusion for users of the 'TOT GUARD' since the user might be led to believe that more than one instruction is applicable. In your proposed revision, the word(sic) 'each of' would be deleted from the warning and the word 'instructions' would be changed to the singular.; Your proposed revision does not make any substantive change in th meaning of the warning specified for the label. Since the proposed change is a minor variation intended to clarify the language for restraints that only need to be labeled with one of the specified instructions, it is permitted.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0670OpenMr. Preston W. Grace, President, White River Distributors, Inc., P.O. Box 1462, River Stadium Drive, Batesville, AR 72501; Mr. Preston W. Grace President White River Distributors Inc. P.O. Box 1462 River Stadium Drive Batesville AR 72501; Dear Mr. Grace: This is in reply to your letter of March 30, 1972, concerning you earlier letter to us of March 6, 1972, which we answered on March 22. You indicate that you have received trucks with identical specifications, but with different GVW ratings, and ask, why is it permissible for a manufacturer to place different GVW ratings on identical vehicles. You state further that, based on our letter, you have concluded that it is the responsibility of the user to see that the GVW rating assigned by the final-stage manufacturer is not violated.; As we indicated to you in our letter of March 22, 1972, there i nothing in the regulations that prohibits a manufacturer from placing different GVW ratings on identical vehicles, as long as the rating in each case meets the requirements of sections 567.4(g)(3) or 567.5(a)(5), whichever is appropriate. Manufacturers may have various reasons for changing the GVWR or GAWR of vehicles they manufacture, and the regulations allow them to do this. As we indicated to you previously, final stage manufacturers such as yourself might resolve this problem by specifying the desired weight ratings in your purchase order.; Your statement that it becomes the user's responsibility to see tha the GVWR assigned by the final stage manufacturer is not violated is essentially correct. However, the requirement for affixing the GVWR and GAWR to a vehicle should not be confused with the requirements pertaining to the overloading of vehicles. The latter are presently primarily a matter of state enforcement, and do not affect the requirements of final stage manufacturers to affix GVWR and GAWR in accordance with Parts 567 and 568.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3056OpenMichael J. Schmitt, Esq., Legal Counsel, Engineering Division, Yamaha Motor Corporation U.S.A., P.O. Box 6555, Cypress, CA 90630; Michael J. Schmitt Esq. Legal Counsel Engineering Division Yamaha Motor Corporation U.S.A. P.O. Box 6555 Cypress CA 90630; Dear Mr. Schmitt: This is in reply to your letter of July 2, 1979, to our former Chie Counsel, Joseph Levin asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108.; You have quoted Column 3 of Table IV with respect to motor cycl headlamps and the specification that the one headlamp the standard requires be located 'on the vertical centerline, except that if two are used they shall be symmetrically disposed about the vertical centerline'. Yamaha would like to equip certain motor cycles with two headlamps, one to be mounted above the other on the vertical centerline with the hope that 'this may increase conspicuity and facilitate safety'. You have asked whether this mounting arrangement conforms with Standard No. 108.; The arrangement you have in mind is not permitted by the Federa lighting standard. 'Symmetrically disposed about the vertical centerline' means that each headlamp is an equal distance from the vertical centerline at the same horizontal location. We believe that this provides better and more evenly distributed forward illumination than the system Yamaha proposes, while being the equivalent in conspicuity.; Sincerely, Frank Berndt, 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.