
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: aiam3974OpenThe Honorable John S. McCain, III, U.S. House of Representatives, Washington, DC 20515; The Honorable John S. McCain III U.S. House of Representatives Washington DC 20515; Dear Mr McCain: Thank you for bringing to our attention the problems experienced b your constituents due to conflicting State laws on motor vehicle window tinting.; The National Highway Traffic Administration (NHTSA) has issued Federal motor vehicle safety standard governing window tinting in new vehicles and replacement equipment, and Federal law also limits the extent to which certain commercial businesses may apply additional tinting. However, Federal law does not preclude individuals from tinting their vehicle windows. That matter is left to the States, and we understand the difficulties that may arise when the tinting laws of adjacent States are inconsistent.; Our agency has been discussing the issue of window tinting with th American Association of Motor Vehicle Administrators, in an effort to better explain the interaction of Federal and State laws in this area. That may also be an appropriate forum in which to consider ways to resolve conflicts between differing State tinting laws. While NHTSA and each state government has a valid interest in preserving its legal authority, we all share a common interest in promoting highway safety and in minimizing inconvenience to traveling motorists. In our view, a well-coordinated and cooperative approach among the various parties can help to address apparent problems in this area.; We will keep you advised of our progress in those discussions. appreciate knowing of your concern in this matter, and I hope you will feel free to contact me if this agency can be of further assistance.; Sincerely, Diane K. Steed |
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ID: aiam2867OpenMr. Robert B. Kurre, Director of Engineering, Wayne Corporation, P.O. Box 1447, Industries Road, Richmond, IN 47374; Mr. Robert B. Kurre Director of Engineering Wayne Corporation P.O. Box 1447 Industries Road Richmond IN 47374; Dear Mr. Kurre: This responds to your recent letter asking whether Safety Standard No 208 applies to side-facing seats in multipurpose passenger vehicle vans. You also ask to be advised of the criteria to be used for the installation of seat belts in these vehicles.; Safety Standard No. 208, *Occupant Crash Protection*, does require sid facing seats in multipurpose passenger vehicles to comply with one of the options under paragraph S4.2.2, since the side-facing seats in question would be considered designated seating positions. If a manufacturer chooses to install seat belts under one of the options of that paragraph, the seat belt assemblies must comply with Safety Standard No 209, *Seat Belt Assemblies*, and Safety Standard No. 210, *Seat Belt Anchorages*.; Safety Standard No. 210 does exempt side-facing seats from its strengt requirements, but all other requirements of the standard would be applicable. However, we strongly recommend that belt anchorages for side-facing seats be of at least equivalent strength to anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. Side-facing seats were excepted from the strength requirements specified in the standard because the forces acting on side-facing seats are different from those acting on forward or rearward facing seats and the requirements and procedures were specifically developed for these latter seats.; Please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5279OpenMr. Richard L. Plath Selecto-Flash, Inc. P.O. Box 879 Orange, NJ 07051; Mr. Richard L. Plath Selecto-Flash Inc. P.O. Box 879 Orange NJ 07051; Dear Mr. Plath: This is in reply to your letter of November 15, 1993 to Taylor Vinson of this Office on trailer conspicuity. You ask for confirmation of several points. Initially, we would like to comment as follows on the 4-point procedure you have outlined: '1) A chassis for purposes of the conspicuity requirement shall be considered to be a trailer.' This is correct. Because the chassis is designed for carrying property and for being towed by a motor vehicle, it is a 'trailer' as defined for purposes of compliance with the Federal motor vehicle safety standards. '2) That the total length of the chassis shall be used in computing the 50 percent coverage of high intensity reflective for each individual side.' This is correct. Under S5.7.1.4.2(a) of Standard No. 108, retroreflective tape 'need not be continuous as long as not less than half of the length of the trailer is covered . . . .' '3) In the case of a 48 foot chassis, the law will thus require a minimum of 24 feet of the approved reflective sheeting to be applied to each side. Further, there shall not be more than 18 inches of either red or silver reflective in a continuous strip and that there shall not be an allowed void of more than 48 inches between modules.' This is partially correct. Under S5.7.1.4.2(a), a minimum of 24 feet of reflective material must be applied to the side of a 48-foot trailer. However, S5.7.1.3(a) requires the colors to be red and white, not red and silver. Further, under S5.7.1.3(b), the permissible lengths of the sheeting are expressed as 'each white or red segment shall have a length of 300 mm +/- 150 mm.' We note that 450 mm is slightly less than 18 inches. Finally, Standard No. 108 does not specify any maximum permissible 'void . . . between modules.' Under S5.7.1.4.2(a), the spaces are to be distributed 'as evenly as practicable.' '4) * * * When the chassis is not loaded with a container, the application of 24 feet per side of a 48 foot chassis of evenly spaced reflective modules would comply with the law as we understand it. It would identify the extreme front and rear portions of the chassis. * * *' This is incorrect. Compliance by an unloaded container chassis with the conspicuity requirements is determined as if the container load were in place. S7.5.1.4.2(a) states that 'at the location chosen for conspicuity treatment , the strip shall not be obscured in whole or in part by other motor vehicle equipment or trailer cargo.' Because the container obscures the gooseneck, the conspicuity treatment mandated by Standard No. 108 cannot identify the extreme front portion of the chassis. Its front termination point will be behind the gooseneck, at a point where it is not obscured by the container. You have correctly stated this with respect to a loaded chassis but it applies to the unloaded chassis as manufactured: '. . . the entire 24 feet (50 per cent of length) shall be applied behind the gooseneck. In general this would mean that the rear 40 foot portion of the chassis would contain the 24 feet of reflective modules. Further we understand that the 50 percent requirement would be satisfied and that additional modules would not have to be applied to the gooseneck.' You conclude that a gooseneck chassis traveling without its container would be in violation of Standard No. 108 if its gooseneck were not marked 'creating a hazard and would violate the requirement stating that a void of no more than four feet is allowable.' You also ask ' i s there a benefit in applying the additional 4 feet of reflective within the rear 40 foot portion of the chassis?' As explained previously, Standard No. 108 does not require marking of the gooseneck of a container chassis, and there is no requirement limiting the spacing between segments of retroreflective material. We believe that the desired conspicuity of the trailer will be maintained by requiring the additional 4 feet of sheeting on the chassis behind the gooseneck when the gooseneck itself will be obscured with the container in place. Standard No. 108 does not prohibit a manufacturer from applying conspicuity treatment to the 8-foot gooseneck of a 48 foot trailer if it wishes to do so, however, the manufacturer is still required to apply not less than 24 feet of material in the 40-foot section behind the gooseneck. We shall be pleased to answer the following four questions you have also raised: '1) Will we need to apply 24 feet of stripping on a 48 foot chassis behind the gooseneck plus an additional 4 feet on the gooseneck?' You will have to apply 24 feet of stripping on the portion of a 48-foot chassis that lies behind the gooseneck, but you are not required to mark the gooseneck. '2) Since a chassis is considered to be treated as a trailer, shouldn't we apply the 24 feet evenly spaced from the extreme rear and front portions of the chassis?' As explained previously, the 24 feet of material is to be applied behind the gooseneck. If you wish to apply evenly spaced conspicuity treatment that includes the gooseneck, you may do so, as long as at least 24 feet of it is behind the gooseneck. '3) Is a tire considered a legal obstruction? If so, can we deduct the distance behind the tire from the 50 percent coverage?' Yes, a tire is 'motor vehicle equipment' within the meaning of S5.7.1.4.2(a) forbidding the obscuring of conspicuity treatment. No, you may not deduct the length of the area obscured by the tire from the 50 per cent coverage. You must include it in the 50 per cent computation. Thus, if a tire would obscure 3 feet of conspicuity material on the side of a 48 foot gooseneck trailer, the manufacturer must apply 24 feet of material in the 37 feet that is behind the gooseneck which is not obscured. We note in passing that the prints submitted for our review by J.Z. Peepas of Selecto-Flash depict conspicuity treatment that is above the top of the tire and apparently not obscured by it. '4) We anticipate that the slide mechanism on an extendable chassis will scrape the reflective film off the chassis. Is the operator then subject to penalties? How will the operator be able to avoid these penalties since they have no control over this process?' You are not required to place conspicuity treatment on the extendable portion of the chassis provided that not less than half of the length of the trailer is covered when the conspicuity treatment is placed elsewhere. In the event that conspicuity treatment is placed on the extendable portion and is damaged when the trailer is in use, the operator will not be subject to any penalties of this agency. Federal regulations governing the use of commercial vehicles in interstate commerce are issued by another agency of the Department of Transportation, the Federal Highway Administration (FHWA). The FHWA requires that vehicles manufactured on or after March 7, 1989, meet the requirements of Standard No. 108 in effect on the date of manufacture of the vehicle (49 CFR 393.11). Therefore, maintenance of the conspicuity treatment on trailers manufactured on or after December 1, 1993, is required by the FHWA. If you wish to write FHWA on this topic, you may address James E. Scapellato, Director, Office of Motor Carrier Standards, FHWA, Room 3107, 400 Seventh Street, SW, Washington, D.C. 20590. The individual states may have regulations in this area as well. We are unable to advise you on State requirements, and suggest that you consult the American Association of Motor Vehicle Administrators, 4600 Wilson Blvd., Arlington, Va. 22203. Sincerely, John Womack Acting Chief Counsel; |
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ID: 2703yOpen Mr. W. Marshall Rickert Dear Mr. Rickert: Thank you for your letter seeking this agency's opinion as to whether the State of Maryland may amend its motor vehicle regulations to permit the installation of aftermarket tinting on motor vehicle windows, for individuals who may desire this for medical reasons. I am pleased to have this opportunity to describe the legal principles that relate to your question. The National Highway Traffic Safety Administration ("NHTSA") is responsible for issuing Federal motor vehicle safety standards that impose requirements for specific levels of safety performance for new motor vehicles and motor vehicle equipment. Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205), which has been in effect since 1968, imposes a minimum level of light transmittance of 70 percent in all areas requisite for driving visibility (which includes all windows on passenger cars). The purpose of this requirement is to ensure adequate visibility through the windows, thereby reducing the risk of a motor vehicle crash. Although Federal motor vehicle safety standards apply directly only to new vehicles and equipment, Federal law also imposes limits on the addition of tinting materials to motor vehicle glazing after vehicles have been purchased by consumers. Pursuant to section 108(a)(2) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1397(a)(2), manufacturers, distributors, dealers, or motor vehicle repair businesses may not "render inoperative" any equipment or element of design installed in compliance with a Federal safety standard. Thus, those businesses may not install tinting that reduces the light transmittance of windows covered by Standard 205 to a level below the Federal requirement of 70 percent, since that would make the windows "inoperative" within the meaning of Standard 205. This Federal prohibition is similar to that imposed by section 22-104 of the Maryland Vehicle Law, which provides: A person may not willfully or intentionally remove or alter any safety device or equipment that has been placed on any motor vehicle . . . in compliance with any law, rule, regulation, or requirement of . . . the United States or of this State . . . unless the removal or alteration is permitted by rule or regulation adopted by the [Maryland Motor Vehicle] Administrator. The "render inoperative" provision of Federal law does not apply to actions by individual vehicle owners. Therefore, each State may regulate the extent to which aftermarket tinting may be applied by vehicle owners to their own vehicles. Thus, although section 22-104 appears to preclude aftermarket tinting by any person if the result would be to reduce the level of light transmittance below 70 percent, Maryland may amend its rules or regulations to permit such tinting by individuals, for medical or any other reasons deemed valid by the State. However, Maryland has no authority to grant any exemptions, including medical exemptions, from the "render inoperative" prohibition of Federal law that applies to commercial entities. Hence, regardless of any provisions of Maryland law, no manufacturer, distributor, dealer, or motor vehicle repair business may legally install window tinting film on a vehicle, unless the vehicle continues to comply with the Federal light transmittance requirements. In adopting Standard 205, NHTSA determined that a minimum light transmittance of 70 percent is necessary to meet the need for motor vehicle safety. This is the same level of light transmittance contained in the Safety Code of the American National Standards Institute. If, as your letter suggests, Maryland is considering permitting vehicle owners to modify their vehicles such that their windows will have a lower level of light transmittance, we would urge you to carefully consider the safety consequences of such an exemption. Please let me know if you need any further information on this subject. Sincerely,
Paul Jackson Rice Chief Counsel ref:205 d:l0/l5/90 |
1970 |
ID: 2878oOpen Mr. Michael Rose Dear Mr. Rose: This responds to your letter, addressed to the Director of the Office of the Federal Register, concerning Federal Motor Vehicle Safety Standard No. l09, New Pneumatic Tires. The National Highway Traffic Safety Administration (NHTSA) is the Federal agency which issued and administers that standard. Your questions are addressed below. By way of background information, NHTSA issues Federal motor vehicle safety standards under the National Traffic and Motor Vehicle Safety Act, l5 U.S.C. l38l et seq. The term "motor vehicle safety standard" is defined by the Act as "a minimum standard for motor vehicle performance, or motor vehicle equipment performance, which is practicable, which meets the need for motor vehicle safety and which provides objective criteria" (section l02(2)). NHTSA does not grant approvals of motor vehicles or motor vehicle equipment. Instead, section ll4 of the Act requires manufacturers to certify compliance of each motor vehicle and item of equipment with all applicable standards. The Act requires that manufacturers exercise "due care" to ensure that their products conform to each applicable standard (section l08(b)(l)). I will address your first two questions together. The questions are: l. In the clause dealing with Test Sample, why are the batch size and sample size not mentioned? 2. Why does the standard make no reference to the frequency of testing. As indicated above, Standard No. l09 is a minimum performance standard. All tires must be capable of meeting the standard's requirements. The purpose of the test sample paragraph (S4.2.2.l) in Standard No. l09 is to indicate that a test set for a compliance test consists of three tires. One tire is checked for physical dimensions and is then subjected to resistance to bead unseating and strength, in sequence. The second tire is subjected to the endurance test, and the third tire is subjected to the high speed test. Paragraph S4.2.2.l is not intended to address the question of how many sets of tires a manufacturer should test as a surveillance procedure during production or what batch size the test sets should be drawn from. A manufacturer is not required to conduct any particular frequency of testing or even to run the actual tests specified by Standard No. l09. Instead, a manufacturer must take whatever steps are necessary to ensure that each of its tires, if tested according to the requirements of the standard, would meet those requirements. (For test purposes, however, any one given tire would only be subjected to one of the three test sequences discussed above.) Since Standard No. l09 includes a number of specific test requirements, it is likely that a manufacturer would find it necessary to do some testing in order to ensure that a tire complied with the standard. For enforcement purposes, NHTSA would test a tire according to the specific test requirements of Standard No. l09. Your third question is as follows: 3. Why does the standard make no reference to tolerances for tyre concentricity? NHTSA's standards cover aspects of performance for which the agency has determined there is a safety need. To date, NHTSA has not determined that there is a need for requirements covering tire concentricity tolerances. We note that tire concentricity appears to be primarily an issue of occupant comfort rather than safety. I hope this information is helpful. Sincerely,
Erika Z. Jones Chief Counsel ref:109 d:7/11/88 |
1988 |
ID: 3298yyOpen Mr. S. Suzuki Your ref: ST-9015/91 Dear Mr. Suzuki: This responds to your letter of October 16, l991, to the Director, Office of Public and Consumer Affairs, with reference to the "Safety Shot" lighting device that you have developed. You have enclosed photographs illustrating three types of this device in operation. In brief, the device consists of a center red highmounted stop lamp, immediately flanked by amber lamps that serve as supplementary turn signal/hazard warning signal lamps. Although the photos are not entirely clear, the device appears to consist of segmented compartments in a common housing, with thicker dividers separating the signal and stop functions. Type I incorporates an L.E.D. and is mounted at the top of the rear window. Type II also incorporates an L.E.D. and is mounted at the bottom of the window. Type III is located at the top of the rear window and uses conventional bulbs for its light source. You have been referred to us by Chrysler Corporation. We assume that you approached Chrysler with a view towards having your device accepted as original motor vehicle equipment. You have asked for our views on whether it is possible to use this device in the U.S. market. In the United States, the applicable Federal motor vehicle safety standard for rear lighting is Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Section S5.4 of Standard No. l08 does not allow a center high-mounted stop lamp to be physically combined with any other lamp or reflective device. Because Safety Shot appears to have a common housing for signalling and stopping functions, the lamps are "combined" within the meaning of the prohibition. This means that the Safety Shot may not be used as original equipment on motor vehicles, and it may not be offered as a replacement for original equipment center highmounted stop lamps (required on each passenger car manufactured on or after September 1, l985). If you wish to sell the Safety Shot as an accessory in the aftermarket, for passenger cars manufactured before September 1, l985, different considerations apply. Installation of the Safety Shot by a manufacturer, distributor, dealer, or motor vehicle repair business is not permitted if it renders inoperative, in whole or in part, the function of any other rear lighting device. The question, therefore, is whether the effectiveness of the function of any other rear lighting device is compromised by the Safety Shot to the extent that the other device's function is rendered, at the minimum, partially inoperative. We note that original equipment amber signal lamps are not prohibited from flashing when the stop lamps are operating. It would not appear that the addition of the Safety Shot to a passenger car manufactured before September 1, l985, would compromise the signals from the original turn signal and stop lamps in a manner to render them, at least, partially inoperative. However, the Safety Shot is subject to regulation by the individual States of the United States in which it is sold or used. We are unable to advise you on State laws, and suggest that you write for an opinion to American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. Motor vehicles are also required to be manufactured to conform to Standard No. 111, Rearview Mirrors. Under this standard, if installation of the Safety Shot prevents the vehicle from meeting the rearview mirror field of view requirements specified, the manufacturer, distributor, dealer, or motor vehicle repair business installing the Safety Shot must install a rear view mirror on the passenger side of the vehicle (as a practical matter, most vehicles in the U.S. are manufactured with this additional mirror). Sincerely,
Paul Jackson Rice Chief Counsel ref:108 d:1/31/92 |
1992 |
ID: 10441Open Mr. Randal Busick Dear Mr. Busick: This responds to your letter of October 14, 1994, concerning whether a belt design would comply with S7.1.2 of Standard No. 208, Occupant Crash Protection, as amended in a final rule published on August 3, 1994 and effective on September 1, 1997 (59 FR 39472). As described in your letter, for this belt design, "the inboard lower FMVSS 210 anchorage is located on the seat frame and thus, as the seat moves fore and aft, the system allows a minimum of two seat belt adjustment positions and the distance between the two extreme adjustment positions of the system is more than 5 cm." The August 3 final rule amended Standard No. 208 to improve the fit and increase the comfort of safety belts for a variety of different sized occupants. After the effective date, S7.1.2 will, in pertinent part, read as follows: ... for each Type 2 seat belt assembly which is required by Standard No. 208 (49 CFR 571.208), the upper anchorage, or the lower anchorage nearest the intersection of the torso belt and the lap belt, shall include a movable component which has a minimum of two adjustment positions. The distance between the geometric center of the movable component at the two extreme adjustment positions shall be not less than five centimeters, measured linearly. As illustrated in the drawing provided with your letter, the inboard anchorage on your seat design is the "the lower anchorage nearest the intersection of the torso belt and the lap belt." It would appear that, under the definition of "seat belt anchorage" in Standard No. 210, Seat Belt Anchorages, the seat would be considered part of the anchorage for your design. Standard No. 210 defines a "seat belt anchorage" as
any component, other than the webbing or straps, involved in transferring seat belt loads to the vehicle structure, including, but not limited to, the attachment hardware, seat frames, seat pedestals, the vehicle structure itself, and any part of the vehicle whose failure causes separation of the belt from the vehicle structure. If the seat is part of the anchorage, and if the seat can be adjusted more than 5 cm, measured linearly, it appears that your design will meet the requirement of S7.1.2. While not directly relevant to your question, agency technical staff raised concerns about a device in the drawing enclosed with your letter. The drawing of the system shows a device labeled "Slider Bar" to which the outboard lower end of the seat belt anchorage is attached. While no detail is provided on this device, agency staff are concerned that the device (which appears to function as the lower outboard anchorage) allows the seat belt webbing attachment to slide freely fore and aft longitudinally. If our interpretation of the drawing is correct, this device may prevent the belt system from meeting the occupant protection requirements of Standard No. 208, as well as prevent the anchorage from meeting the anchorage location requirements of S4.3 of Standard No. 210. Finally, the device may introduce slack in the belt system, preventing the belt from adequately securing a child safety restraint in the seat or providing complete protection to an adult. I hope this information has been helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely,
Philip R. Recht Chief Counsel Enclosure ref:208 d:1/5/95
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1995 |
ID: 1786yOpen The Honorable Leon E. Panetta Dear Mr. Panetta: This letter responds to your inquiry on behalf of your constituent, Mr. Botelho. You asked whether Federal regulations require mirrors to be placed on the right side of vehicles and whether such mirrors must be convex in nature. Mr. Botelho expressed his objection to requiring convex mirrors, because he believes convex mirrors distort images and cause objects to appear further away than they actually are. I am pleased to have this opportunity to explain this requirement and its background for you. Standard No. 111, Rearview Mirrors (49 CFR /571.111, copy enclosed)) establishes performance and location requirements for the rearview mirrors installed in new vehicles. Specifically, a passenger car whose inside rearview mirror does not meet the field of view requirements of section S5.1.1 must have an outside mirror on the passenger side of either unit magnification or a convex mirror. In a September 2, 1982 final rule amending Standard No. 111, the National Highway Traffic Safety Administration (NHTSA) explained that convex mirrors offer safety benefits by providing an expanded field of view to the rear, thereby reducing the need for the driver to turn around to view the rear directly. On the other hand, some users of convex mirrors that were used to the images shown by conventional plane mirrors incorrectly perceived that the object shown in the convex mirror was further to the rear than it actually was. Additionally, some users of convex mirrors experienced double vision, eyestrain, and nausea. After considering these potential advantages and disadvantages, NHTSA amended Standard No. 111 so that it does not require any vehicle to be equipped with convex mirrors, but it permits the use of convex mirrors on the passenger side of cars and light trucks, provided that the convex mirror meets certain additional requirements. The additional requirements applicable to convex mirrors on the passenger side of cars and light trucks are: 1. A maximum radius of curvature for the convex mirror. This limits the range of convexities to which drivers will be exposed. It also ensures that the field of view will be noticeably greater than for a plane mirror. 2. A minimum radius of curvature for the convex mirror. This ensures that the image size in the convex mirror will be adequate and distortion will not be excessive. 3. A stringent maximum permissible variation in the radius of curvature over the surface of the convex mirror. This requirement, which is more stringent than the European requirement in this area, also ensures that convex mirrors will have low distortion. 4. A warning etched on the convex mirror that objects shown in the mirror are closer than they appear. This requirement ensures that the driver who may not be familiar with convex mirrors will not be misled by the image size of the convex mirror and the apparent distance to the object. Hence, we agree with Mr. Botelho that the areas he has identified are potential problems unique to convex mirrors. However, our standard includes special requirements for convex mirrors to minimize the potential problems identified by Mr. Botelho and other potential problems that were identified in research studies of convex mirrors. We are not aware of any data showing that convex mirrors that comply with those special requirements present any unacceptable problems for drivers. I hope this information is helpful. If you have any further questions or need any additional information on this subject, please let me know. Sincerely,
Erika Z. Jones Chief Counsel Enclosure /ref:111 d:4/l7/89 |
1970 |
ID: 12-001952 Matheny capacity includes driver (Standard No. 217)OpenMr. Larry W. Fowler Matheny Motors 3rd & Ann Streets P.O. Box 1304 Parkersburg, WV 26102-1304 Dear Mr. Fowler: This responds to your letter to the National Highway Traffic Safety Administration (NHTSA) asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus Emergency Exits and Window Retention and Release. We apologize for the delay in responding; we regret that we did not receive the January 19, 2012 letter you had sent. You ask for clarification of the term seating capacity as used in Table 1 and Table 2 of FMVSS No. 217, i.e., whether the driver is considered part of the seating capacity of a bus for purposes of determining the additional emergency exits needed under S5.2.3 of the standard. As explained below, our answer is yes, the driver seat is included as part of the seating capacity. In 1992, FMVSS No. 217 was amended to revise the minimum requirements for school bus emergency exits.[1] Instead of requiring all school buses to have the same number of exits, the standard was amended to establish minimum emergency exit space based on the seating capacity of each bus. The amendment determined the number of additional exits using a calculation that was based on the designated seating positions in the bus. Under our regulations, we consider a drivers seat to be a designated seating position.[2] In a 1995 amendment, NHTSA replaced the calculations with simple tables, including Tables 1 and 2.[3] The agency explained that the number of exits required by the tables would be derived from the existing requirement. There was no discussion of changing seating capacity to exclude the drivers seat. Thus, we interpret Tables 1 and 2 as simply reflecting the assumptions and calculations that were used previous to the tables. That being the case, seating capacity includes the drivers seat. It makes sense for seating capacity to include the drivers seat for purposes of Table 1 and 2. In an emergency, the driver will be among the occupants needing to exit the vehicle quickly. Including the drivers position in the calculation supports the goal of having sufficient exits to accommodate the occupants of the bus. I hope this information is helpful. If you have any further questions, please do not hesitate to contact Ms. Deirdre Fujita of my staff at (202) 366-2992. Sincerely, O. Kevin Vincent Chief Counsel Dated: 8/14/12 Ref: Standard No. 217 |
2012 |
ID: 1985-02.41OpenTYPE: INTERPRETATION-NHTSA DATE: 06/10/85 FROM: AUTHOR UNAVAILABLE; Jeffrey R. Miller; NHTSA TO: Russ L. Bomhoff TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 18, 1985, concerning the applicability of our safety standards to a passenger van you are designing. Specifically, you asked whether you can install a stationary, side-facing passenger seat with lap safety belts. As discussed below, you can use such a seat with a lap safety belt, but its use would be affected by Federal Motor Vehicle Safety Standard Nos. 207, Seating Systems, 208, Occupant Crash Protection, 209, Seat Belt Assemblies, and 210, Seat Belt Assembly Anchorages. A copy of each of those standards is enclosed. Standard No. 207 specifies performance requirements for seats, their attachment assemblies, and their installation, to minimize the possibility of seat failure resulting from crash forces. This standard is applicable to seats installed in vehicles including vans, but section 4.2 of Standard No. 207 excludes side-facing seats from the general seat strength requirements of the standard. However, there are other requirements in the standard which may apply to side-facing seats. For example, paragraph S4.3 requires a restraining device if the seat has a hinged or folding seat or seat back. Standard No. 208 sets requirements for the installation of safety belts in motor vehicles. You stated that the vehicle you are designing is a passenger van that carries under 10 passengers. If your vehicle carries a total of 10 persons (9 passengers and a driver) it would be considered either a multipurpose passenger vehicle (MPV), if it is manufactured on a truck chassis or has special features for occasional off-road use, or a passenger car. If your vehicle is a passenger car, section 4.1.2.3(c) of the standard provides that each designated seating position for rear passengers can have a Type 1 (lap) or Type 2 (lap/shoulder safety belt) that conforms with Standard 209 and the adjustment and latch mechanism requirements of S7.1 and S7.2 of Standard No. 208. If your vehicle is a MPV, then S4.2.2, for MPV's with a GVWR greater than 10,000 pounds or less, or S4.3, for MPV's with a GVWR greater than 10,000 pounds, provides that each designated seating position for rear passengers can have a Type 1 or Type 2 safety belt that conforms to Standard No. 209. Standard No. 210 sets performance requirements for safety belts anchorages in passenger cars, MPV's, trucks, and buses. The standard exempts side-facing seats from its strength requirements specified in S4.2, but all other requirements of the standard apply to side-facing seats. We strongly recommend that belt anchorages for side-facing seats be of at least equivalent strength to the anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. ENCLS.
PRECISION PATTERN INC. April 18, 1985 Office of Chief Counsel NHTSA Dear Sir: This letter is a request for a ruling concerning a safety standard as applicable to passenger van seating. Specifically, I need to know if putting a stationary side facing seat, with lap seat belts is legal and acceptable. This side facing seat would be equipped with lap seat belts if necessary. It would be located at the rear of the vehicle, behind the drivers seat. The vehicles in question are for under 10 passengers, and are of 15', 17', and 20' lengths. We are in the middle of a design project on this and your prompt attention to this matter would be greatly appreciated. Please call 316/ 942-0905 if you have any questions. Thank you. Mr. William Smith in your engineering dept. requested that I consult you for a permanent ruling. His interpretation of the rules would allow the use of this side facing seat. Russ L. Bomhoff (Graphics omitted) |
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.