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: aiam4850OpenMr. Saburo Inui Corporate Manager Toyota Motor Corporate Services of North America, Inc. 1850 M Street, N.W. Washington, D.C. 20036; Mr. Saburo Inui Corporate Manager Toyota Motor Corporate Services of North America Inc. 1850 M Street N.W. Washington D.C. 20036; Dear Mr. Inui: This responds to your letter of February 20, 1991, wit respect to an interpretation of Standard No. 108 as it relates to High Intensity Discharge Headlamp (HID) designs contemplated by Toyota. You explained these designs in greater detail to NHTSA staff members in a meeting with them on February 20. Standard No. 108 defines an 'integral beam headlamp' as one which is neither a sealed beam headlamp nor one equipped with a standardized replaceable light source, but one which is a 'headlamp comprising an integral and indivisible optical assembly, including lens, reflector, and light source.' You have presented two HID headlamp designs, and have asked whether these lamps are 'integral beam headlamps' as defined by Standard No. 108. These lamps differ from conventional headlamps by having ballast, consisting of a 'starter' affixed to the rear of the headlamp, connected to a 'converter,' which is separated from the headlamp-starter unit. Because of space limitations, it may not be feasible to integrate the ballast into the headlamp enclosure. On one of these headlamps (Figure 2) the starter and converter are directly connected to each other by a 'hard wire' while in the other (Figure 3), the starter and converter are connected by 'hard wires' that meet at a connector between the two. In this design, the ballast units would be installed separately, then permanently joined by a connector, which could not be separated without destroying the connector. You believe that both designs are 'integral beam headlamps.' The phrase 'optical assembly' in the definition of 'integral beam headlamp', in our view, encompasses all lamp components other than the power source which are required for illumination of the headlamp. This means that an 'optical assembly' includes the ballast. Although the lamp, starter, and converter may be permanently attached to each other, and could be considered 'indivisible,' and the starter could be considered to be 'integral' with the lamp body, the positioning of the converter at some distance from the starter, as shown in your Figure 2 and Figure 3, does not render it 'integral' within the meaning of the definition, unless it is permanently attached to the starter. However, a design which had a connector as in your Figure 3 and described in your letter, would be considered both 'integral' and 'indivisible' if its individual components were not permanently attached to each other until the installation of the device in a motor vehicle, providing that any portion of the device could not be subsequently detached without damage sufficient that the entire device would have to be replaced. This would apply to either original or replacement equipment. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam0540OpenMr. R.A.C. Dandy, Senior Engineer, Head of Mechanical Section, British Standards Institution, Hemel Hempstead Centre, Maylands Avenue, Hemel Hempstead, Herts, England; Mr. R.A.C. Dandy Senior Engineer Head of Mechanical Section British Standards Institution Hemel Hempstead Centre Maylands Avenue Hemel Hempstead Herts England; Dear Mr. Dandy: This is in reply to your letter of July 26, 1972, on the subject o seat belt retractor testing under S5.2(k) of Motor Vehicle Safety Standard No. 209.; Your outline of the emergency locking retractor test procedure i essentially correct. During the initial 5,000 cycles, however, the belt is to be retracted completely, even though some vehicle installations may prevent complete retraction. The assumption in (3)(ii) of your letter is therefore incorrect.; The remaining points in your interpretation are correct. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5312OpenMr. Bob Carver Product Engineering Wayne Wheeled Vehicles 13311 Industrial Parkway Marysville, OH 43040; Mr. Bob Carver Product Engineering Wayne Wheeled Vehicles 13311 Industrial Parkway Marysville OH 43040; "Dear Mr. Carver: This responds to your letter of January 8, 1994 asking two questions concerning a recent amendment to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413, November 2, 1992). Your questions and the response to each follow. 1. There's some confusion here in our engineering department regarding the interpretation of the 'Daylight Opening' and 'Unobstructed Opening' as it applies to the new side emergency door specification in FMVSS 217. Page 2 shows the allowable obstruction and the context in which 'Daylight Opening' and 'Unobstructed Opening' are used. Page 3 shows some measurements of our seats placed according to the '30 cm minimum' shown on page 2. Page 4 shows four different interpretations of the 'Unobstructed Opening' area. Depending on the interpretation, between 9 and 15 people may be accommodated by a side emergency door. My question is this: of the four possibilities shown, which definition of the 'Unobstructed Opening' area is correct? Mr. Hott indicated definition 4. The term 'daylight opening' is defined in the Final Rule as 'the maximum unobstructed opening of an emergency exit when viewed from a direction perpendicular to the plane of the opening.' An obstruction in this context would include any obstacle or object that would block, obscure, or interfere with, in any way, access to that exit when opened. In determining the 'maximum unobstructed opening of an emergency exit,' we would subtract, from the total area of the opening, the area of any portions of the opening that cannot be used for exit purposes as a result of the obstruction. The area measurements would be taken when viewed from a direction perpendicular to the plane of the opening. Your question specifically concerns how the 'maximum unobstructed opening' of a side door is measured when the opening is partially obstructed by a seat. In the case of the illustrated door exit, occupants would use the exit by movement along the floor. This would be considered in determining the extent of an obstruction. None of the four examples you enclosed with your letter correctly illustrates the area that would be credited for the illustrated exit. The following regions would not be credited for this exit: (1) the area visually obstructed by the seat, (2) your region A2, an area bounded by a horizontal line tangent to the top of the seat back, a vertical line tangent to the rearmost portion of the top of the seat, the upper edge of the door opening, and the edge of the door forward of the seat, (3) your region A5, an area bounded by the seat back, a horizontal line tangent to the top of the seat back, and the edge of the door forward of the seat, and (4) your region A8, an area bounded by the seat leg, the floor, the lower edge of the seat bottom, and the edge of the door forward of the seat. Because the seat would make the last three regions unusable as exit space for a person traveling along the floor of the bus towards the exit, they would not be credited for that exit. You should be aware that the agency published a notice of proposed rulemaking to amend Standard No. 217 on December 1, 1993 (58 FR 63321). The notice proposed two alternate means for determining the maximum amount of area that will be credited for all types of emergency exits on school buses. The agency is currently reviewing the comments received in response to this notice. I am enclosing a copy of this notice. 2. Here is an excerpt from FMVSS 217 S5.5.3(a): 'Each school bus ....shall have the designation 'Emergency Door' or 'Emergency Exit' as appropriate, .... For emergency exit doors, the designation shall be located at the top of, or directly above, the emergency exit door on both the inside and outside surfaces of the bus..... For emergency window exits, the designation shall be located at the top of, or directly above, or at the bottom of the emergency window exit on both the inside and outside surfaces of the bus.' I've seen a two-sided sticker used by other bus manufacturers. It is applied on the inside surface of a window and the same image 'Emergency Door' or 'Emergency Exit' can be read from both inside and outside the bus. Is it permissible for us to use this sort of decal, assuming it meets all other (i.e., FMVSS 302)? The answer to your question is yes. The agency addressed this issue in an October 2, 1978, letter to Mr. E.M. Ryan of Ward Industries, Inc. I am enclosing a copy of this letter. I hope you find this information helpful. If you have any other questions, please contact Walter Myers of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures"; |
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ID: aiam0110OpenWarren M. Heath, Commander, Engineering Section, California Highway Patrol, P.O. Box 898, Sacramento, CA 95804; Warren M. Heath Commander Engineering Section California Highway Patrol P.O. Box 898 Sacramento CA 95804; Dear Commander Heath: This is in response to your letter of August 19 inquiring as to th certification responsibility of manufacturers of assemblers of dune buggy kits with respect to conformance with the Federal Motor Vehicle Safety Standards. But the issue you raise is far broader and involves the whole area of owner-assembled motor vehicles.; You have stated:>>>It is our interpretation that Federal Standard 10 is not applicable to dune buggies that are owner-constructed or reconstructed for the builders personal use.'<<<; This interpretation is incorrect. It is a violation of sectio 108(a)(1) of the National Traffic and Motor Vehicle Safety Act of 1966 for any person to:; >>>'...introduce or deliver for introduction in interstat commerce...any motor vehicle...manufactured [or assembled] on and after the date any applicable Federal motor vehicle safety standard takes effect...unless it is in conformity with such standard...'<<<; This means that the final assembler of a dune buggy, whoever he is must insure that the completed vehicle conforms to all applicable Standards including No. 108. In the case of dune buggies, this means Standards applicable to multipurpose passenger vehicles since a dune buggy is 'constructed...with special features for occasional off-road operation.' (23 C.F.R. S255.3(b)).; It is our understanding that a dune buggy consists of a newl manufactured body mounted on the modified chassis of a passenger car previously in use. An issue is raised by the facts that dune buggies are assembled from both new and used items of motor vehicle equipment and that there is language in the Act which appears to exempt 'any motor vehicle or item of motor vehicle equipment after the first purchase of it in good faith for purposes other than resale' (section 108(b)(1). However, since the modification involving used components goes far beyond customizing a used vehicle and results in the end product having a different classification under the Federal Standards and a different purpose than the original vehicle a dune buggy is a 'new' motor vehicle for purposes of the Act.; Continuing your interpretation you further state: >>>'However, those sold as kits or by a manufacturer are required t comply with Federal Standard 108.'<<<; Only assembled vehicles are required to conform to most Federa Standards including No. 108, and there is no legal requirement under the Act that a kit seller furnish lighting equipment meeting the various SAE requirements specified in that Standard. Some Federal Standards, however, do establish requirements applicable to equipment items as well as to assembled vehicles. If a kit manufacturer furnishes hydraulic brake hoses (Standard No. 105), new pneumatic tires (Standard No. 109), glazing materials (Standard No. 205), seat belt assemblies (Standard No. 209), and wheel discs, wheel covers, or hub caps (Standard No. 211), then these items must conform to the applicable Standard.; Finally, there appears to be some misunderstanding of the certificatio required by section 114 of the Act. This certification is required to be furnished only by a manufacturer, or distributor, and only to a distributor or dealer upon delivery of a motor vehicle or equipment item to which a Standard or Standards are applicable. No certification is required to be given by a manufacturer to a party not a distributor or dealer. Nor is there any requirement that the assembler per se certify the vehicle. This of course, does not relieve the assembler of his independent obligation to insure that the assembled vehicle meets Federal Standards.; I hope this answers your questions. Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel for Regulations |
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ID: aiam0405OpenMr. Charles A. Slater, Jr., Vice President - Engineering, Peterson Manufacturing Company, 4515 East 75th Terrace, Kansas City, MO, 64132; Mr. Charles A. Slater Jr. Vice President - Engineering Peterson Manufacturing Company 4515 East 75th Terrace Kansas City MO 64132; Dear Mr. Slater: In reply to your letter of July 9, you are correct in assuming 'it wil still be permissible to illuminate motorcycle license plates from the bottom even after January 1, 1973.'; The installation requirements of Standard No. 108, as set out in SA Standard 587d, License Plate Lamps, March 1969, do not apply to motorcycles and motor driven cycles.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2438OpenMr. Arthur C. Mertz, Executive Vice President, National Association of Independent Insurers, 2600 River Road, Des Plaines, IL 60018; Mr. Arthur C. Mertz Executive Vice President National Association of Independent Insurers 2600 River Road Des Plaines IL 60018; Dear Mr. Mertz: This is in response to your letter of September 23, 1976, concernin petitions for reconsideration of 49 CFR Part 581, *Bumper Standard* (41 FR 9346, March 4, 1976).; Your letter indicated opposition to any agency action on petitions fo reconsideration of Part 581 that would reopen the issue of the standard's content. You stated that should a decision be made by the agency to reconsider Part 581, additional public hearings would be in order before any final action was taken on the standard.; I assure you that no substantive revision of Part 581, based upo petitions for reconsideration, would be made without first proposing the change and providing opportunity for interested persons to comment. I cannot project at this time whether a public meeting would be the best forum in which to receive comments should the agency decide to propose an amendment to Part 581. However, you may be confident that the agency would seek and thoroughly consider comments by your organization and all interested persons before taking final action.; Sincerely, John W. Snow, Administrator |
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ID: aiam5607OpenMilford R. Bennett, Director Safety Affairs and Safety & Restraints Center General Motors Corporation 30200 Mound Road Warren, Michigan 48090-9010; Milford R. Bennett Director Safety Affairs and Safety & Restraints Center General Motors Corporation 30200 Mound Road Warren Michigan 48090-9010; Dear Mr. Bennett: This responds to General Motors' (GM's) May 19, 199 letter asking whether a sunshade device is permitted under the 70 percent light transmissibility requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials. You describe the device as a screen-like device that is stowed in the back panel shelf area below the rear window and that can be electrically raised and lowered by a driver operated switch. The light transmissibility through the combination of the rear window and the raised sunshade is less than 70 percent. The short answer to your question is that the device is permitted. Although you note earlier agency interpretations stating that windows with sunshades must still comply with Standard No. 205, you believe that the standard does not apply to your device. You state that those interpretations were distinguishable because the other shading devices were attached to the window, while your device is not. You are correct in your assertion that installation of your sunshade would not cause a noncompliance with Standard No. 205. The purpose of the 70 percent light transmissibility requirements in Standard No. 205 is to ensure that the driver can see 70 percent of the incident light through the windows that are requisite for driving visibility, under all conditions of lighting. However, the test procedures do not incorporate an in-vehicle test. Instead, they contemplate testing only the glazing itself. Your mesh screen sunshade need not comply with the standard (because it does not meet the definition of glazing) or in combination with the rear window (because it is not attached). Although our standards do not prohibit this device, we have some safety-related concerns with its use in inappropriate situations. NHTSA hopes that GM plans to take steps to minimize the likelihood that the sunshade will be raised in such situations. I hope this information is helpful. If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam4915OpenWilliam Engel, Assistant Chief Covington Fire Department 100 E. Robbins St. Covington, KY 41011; William Engel Assistant Chief Covington Fire Department 100 E. Robbins St. Covington KY 41011; "Dear Mr. Engel: This responds to your letter asking whether Federa Motor Vehicle Safety Standard No. 206, Door Locks and Door Retention Components, requires door locks on fire trucks. Safety Standard No. 206, which applies to all passenger cars, multipurpose passenger vehicles and trucks, does not exclude fire trucks. Thus, new fire trucks are covered by the standard's general requirement that 'components on any side door leading directly into a compartment that contains one or more seating accommmodations shall conform to this standard.' S4 Standard No. 206 does not apply, however, to certain types of doors which are often found on fire trucks. Since your letter did not provide any details about the design of the specific doors to which you refer, I am unable to determine whether any of the doors on those fire trucks would be subject to Standard No. 206's requirements. For your information, I have enclosed two letters from this office which discuss the applicability of Standard No. 206 to specific doors on fire trucks in more detail. The two letters are an August 13, 1980 letter to Mr. Steenbock and a February 11, 1988 letter to Ms. Salvio. The National Highway Traffic Safety Administration has not adopted any amendments to Standard No. 206 that affect the accuracy of the information contained in these letters. I have also enclosed a current copy of Standard No. 206. I hope this information is helpful. Please contact Elizabeth Barbour of my staff at this address or by telephone at (202) 366-2992 if you have further questions. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam0055OpenMr. Dick Romney, Sales Manager, Utility Body Company, 901 Gilman Street, Berkeley, CA 94710; Mr. Dick Romney Sales Manager Utility Body Company 901 Gilman Street Berkeley CA 94710; Dear Mr. Romney: Thank you for your letter of March 6, 1968, to Mr. George C. Nield concerning the additional clearance lamps and reflectors that you have been requested to install on vehicles shipped to Hawaii.; Referring to the drawing attached to your letter, the use of clearanc lamps as shown does not appear to impair the effectiveness of the lighting equipment required by Motor Vehicle Safety Standard No. 108, provided (1) the two lamps on front of the body are *amber* in color, and (2) the lamp on the rear of the body is red in color. Also, use of the amber reflex reflector on front of the body would not appear to impair the effectiveness of the required equipment. Paragraph S3.1.2 of the Standard states: 'No additional lamp, reflective device, or associated equipment shall be installed if it impairs the effectiveness of the required equipment.' This requirement applies to all applicable vehicles, including those owned by a State.; On your drawing, it appears that you have inadvertently indicated a re color for the clearance lamps on the front of the body. Use of red lamps at the locations shown would impair the effectiveness of the required equipment, since red lamps are used, in accordance with the standard, to designate the rear of the vehicle.; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the Standard.; Thank you for writing. Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance; |
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ID: aiam2068OpenMr. Tokio Iinuma, 560 Sylvan Avenue, P. O. Box 1606, Englewood Cliffs, NJ 07632; Mr. Tokio Iinuma 560 Sylvan Avenue P. O. Box 1606 Englewood Cliffs NJ 07632; Dear Mr. Iinuma: This is in response to your letter of August 27, 1975, requesting a interpretation of Standard No. 219 with respect to certain of your test results.; The primary purpose of Standard No. 219 is to protect vehicle occupant from impact with vehicle parts that have penetrated into the passenger compartment through the windshield during a crash. The inner surface of the windshield is the area of interface between the windshield and the passenger compartment. Therefore, the standard is designed to ensure that nothing penetrates into the passenger compartment by precluding penetration of the inner surface of the windshield below the protected zone in a crash test.; In Case 1, although the windshield below the protected zone wa cracked, nothing penetrated the inner surface of the windshield. therefore, it would appear that the windshield is in compliance with S5 of Standard No. 219.; Similarly, in case 2, it appears that the object did not penetrate th inner surface of the windshield, although the windshield was deformed. Therefore, it would appear that the vehicle is also in compliance.; We hope this information is of assistance. Please contact us if yo have any further questions.; Sincerely, Frank A. Berndt, Acting Chief 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.