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: aiam5454OpenMr. Rishi Gupta Autolite (India) Limited D-483 Road No. 9-A Vishwalkarma Industrial Area Jaipur 302 013 India; Mr. Rishi Gupta Autolite (India) Limited D-483 Road No. 9-A Vishwalkarma Industrial Area Jaipur 302 013 India; Dear Mr. Gupta: This is in reply to your FAX of August 29, 1994, t Richard Van Iderstine of this agency. For future reference, requests for interpretations of U.S. Federal motor vehicle safety regulations should be addressed to the Office of Chief Counsel. You have asked whether the size and types of aiming pads you propose to place on headlamps manufactured by Autolite conform to DOT specifications. You describe these headlamps as 'a 7' round and a 200 x 142 mm rectangular replaceable halogen sealed beams which use a replaceable halogen bulb (HB2).' You enclosed diagrams showing 'aiming pad's position as per SAE J1383 - 1992' (Figures 1 and 3), and in the manner you wish to place them on the Autolite lamps (Figures 2 and 4). We understand that these replaceable bulb headlamps are intended to be sold as replacements for sealed beam headlamps of the same dimensions. Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment, is the DOT specification that applies to Autolite's headlamps. The aimability performance requirements for non-sealed beam headlamps are found in S7.8. of Standard No. 108. S7.8 allows any aiming pad pattern that will fit on the headlamp and that will allow any one of the available aiming adapters described in SAE J602 to be used on the headlamp. Specifically, S7.8.1 in pertinent part allows non-sealed beam headlamps to be equipped with aiming pads to be used with the photometric procedures of SAE J1383 APR85 (not '1992' as you wrote) when being tested for photometric compliance, and to serve for the aiming reference when the lamp is installed on a motor vehicle. S7.8.5 allows an installed headlamp system to be aimable with an externally applied aiming device. Under S7.8.5.1, this aiming device shall be the equipment specified in SAE Standard J602 OCT80 Headlamp Aiming Device for Mechanically Aimable Sealed Beam Headlamp Units. You write that the aiming pad sizes and types you wish to use are identical to those on headlamps sold by Hella, and that ETL Testing Laboratories has told you that the aiming pad positions and types meet DOT specifications. This indicates that Autolite's headlamps would be mechanically aimable with SAE J602 equipment, and therefore permissible as meeting Standard No. 108. We recommend that Autolite verify mechanical aimability with SAE J602 equipment before certifying compliance with Standard No. 108. Our engineering staff has reviewed your letter and asks that we point out the following errors in Autolite's Figures Nos. 2 and 4. Under both Figures, there is a reference to 'HB-2 (H4 P43t).' The HB2 light source is not the same as the H4 P43t light source. The HB2 is a light source permitted by Standard No. 108 while the H4 P43t is not permitted by the Standard for motor vehicles. Under the drawing, the dimension '68.5' should be '68.58 +/- 0.51' (see Figure 4-4 of Standard No. 108). The dimensions of '32' and '52.0' must be the sum of two dimension 'A's from Figure 4-4, thus the sum is 42.16 +/- 0.25 + 42.16 +/- 0.25 = 84.32 +/- 0.50, not 84 as nominally calculated. Finally, with respect to Figure 4 only, because this lamp is intended to replace a 200 x 142 mm sealed beam lamp, the position of the aiming pads are not, but should be identical to the 200 x 142 mm sealed beam to facilitate mechanical aim when only one headlamp is replaced. Sincerely, Philip R. Recht Chief Counsel; |
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ID: aiam2104OpenMr. John B. White, Engineering Manager, Technical Information Dept., Michelin Tire Corporation, P.O. Box 3467, New Hyde Park P.O., New York 11040; Mr. John B. White Engineering Manager Technical Information Dept. Michelin Tire Corporation P.O. Box 3467 New Hyde Park P.O. New York 11040; Dear Mr. White: This is in response to your letter of October 17, 1975, concerning th importation into the United States of tires that will be mounted on trucks intended for export from the United States.; 49 CFR Part 571.7(d) and Section 108(b)(5) of the National Traffic an Motor Vehicle Safety Act of 1966 specify that no Federal Motor vehicle Safety Standards (FMVSS) apply to; >>> a motor vehicle or item of motor vehicle equipment intended solel for export, and so labeled or tagged on the vehicle or item itself and on the outside of the container, if any, which is exported.<<<; Therefore, tires which Michelin manufactures for sale directly to truck manufacturer who will mount them on trucks which are intended solely for export need not comply with Standard No. 119, *New Pneumatic Tires for Vehicles Other than Passenger Cars*. When imported and shipped to the truck manufacturer, the tires must bear a label or tag indicating intent to export. Such a label must also appear on the outside of the container, if any, in which the tires are shipped. Importation of such tires is permitted by 19 CFR 12.80(b)(1)(ii), provided they are so labeled. A label need not remain on the tires after they have been mounted on the trucks, provided that the trucks bear similar labels.; Because these tires are not subject to any FMVSS and are beyond th scope of any expected defect notification and remedy program, Michelin Tire Corporation is not subject to the requirements of 49 CFR Part 574, *Tire Identification and Recordkeeping*, with respect to them.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0139OpenMr. Eizuke Niguma, Manager, Technical Service Department, Export Division, Toyo Kogyo Company, Limited, 6047 Fuchi-Maki, Aki-Cun, Hiroshima, Japan; Mr. Eizuke Niguma Manager Technical Service Department Export Division Toyo Kogyo Company Limited 6047 Fuchi-Maki Aki-Cun Hiroshima Japan; Dear Mr. Niguma: Thank you for your letter of November 30, 1968 (your reference No GSAE-26) requesting information to a number of questions reletod (sic) to the Federal Motor Vehicle Safety Standards. I regret that we did not receive your October 5, 1968 letter and that the pressure of work has delayed my answer to your most recent letter.; I am glad to send you the following information: >>>a. MVSS No. 112 - Headlight Concealment Devices. 1. It is stipulated in S.4.6 that 'each headlamp concealment devic shall, within an ambient temperature range of -20 to +120 degrees F., be capable of being fully opened in not more than three seconds after actuation of the mechanism described in S.4.3.' With regard to the temperature condition at the time of a test, if only the ambient temperature satisfies the said temperature conditions, is it all right to pay no regard to other conditions, such as the sticking of frost, ice, etc.?; ANSWER: It is only necessary that the ambient temperature condition (-20 to +120 degrees F.) be satisfied at the time of the test.; b. MVSS No. 114 - Theft Protection. 1. With regard to the stipulation in 5.4.2 that 'The prime means fo deactivating the car's engine or other main source of motive power shall not activate the deterrent required by S.4.1(b),' we have provided the ignition switch with four stages as shown in the sketch below: our key-locking system is of the mechanism that the system does not activate at the stage 'Off', activates only at the stage, 'Lock' and satisfies S.4.4. Does this mechanism conform to S.4.2?; ANSWER: The system as you describe it appears to conform to S4.2 however, the Bureau does not issue approvals of any specific system, and the development of equipment to comply with this requirement is the responsibility of the individual manufacturer.; 2. With reference to the stipulation in S.4.1. 'Each passenger ca shall have a key-locking system that, whenever the key is removed, will prevent ----.', we would like to know whether or not we must provide such a mechanism as the key can be removed only at the stage 'Lock' and cannot at the stage 'Off'.; ANSWER: A locking system having such a position that the key may b removed without activating either the cars' steering lock or its self-mobility lock would not conform to the standard in its present form, since paragraph S4.1 of the standard requires each car to have a key locking system that, whenever the key is removed, will prevent either steering or self-mobility of the car, or both.; c. MVSS No. 201 - Occupant Protection in Interior Impact 1. With regard to the interpretation of the stipulation in S.3.1 '___ the deceleration of the head form shall not exceed 80 g for more than 3 milliseconds,' when the deceleration wave -- shown in the chart below -- is obtained.; in case delta t sub 1 < 3 milliseconds, we interpret that the standard is satisfied even when delta t sub 1 delta t sub 2 + delta t sub 3 + ___ = sigma delta t sub i > 3 milliseconds.; Is our interpretation correct? (Illustration omitted) ANSWER: Your interpretation is correct. The standard permits more tha one peak that exceed 80g which, cumulatively, may add to more than 3 milliseconds. No single peak may continuously exceed 80g for more than a 3 millisecond duration.; 2. When the areas stipulated in S.3.1.1.(d) --' Areas outboard of an point of tangency on the instrument panel of a 6.5 inch diameter head form tangent to an inboard of vertical longitudinal plane tangent to the inboard edge of the steering wheel,' -- are illustrated, which of the following hatched portions in the figures below is in conformity to the stipulation? (Illustration omitted); ANSWER: Figure (a) is correct for the inboard side. Presen requirements do not apply to the area outboard of the steering wheel on the instrument panel.; d. MVSS No. 207 - Anchorage of Seats. S.3.3 Folding and hinged seats. Except for folding auxiliary *seats an seats with backs which are adjustable for occupant comfort only*.; 1. Is it correct to interpret that the underlined part is referring t seats with backs of reclining mechanism enabling to adjust the angle of the back?; ANSWER: Yes. 2. Or, should we interpret that the seats with reclinable backs com under the hinged seats?; ANSWER: No. 3. a. In the case of car with four doors, if the front seats are thos with reclinable backs, these are presumed to be the ones corresponding to (1). Is this interpretation correct?; ANSWER: Yes. S.3.3.1 The release control shall be readily accessible to the occupan of that seat and *to the occupant of any seat immediately behind that seat*.; 1. The above stipulation is presumed to be laid down for the egress o the passengers on the rear seat. Therefore, when the reclining seats are installed in a four-door car, we would like to consider it unnecessary to pay regard to the underlined part. Is this interpretation correct?; ANSWER: Yes. 2. In the case of a two-door car, if the control which can be easil operated by passengers on the rear seat is installed only on one side (the right side), the passengers on the rear seat can operate the control by moving to the right side. Consequently, we consider it sufficient to install only on the right side the control which is easily accessible to the passengers on the rear seat. Is this interpretation correct?; ANSWER: In the case of a two-door car, for a split back or bucket sea arrangement, where both seat backs fold, a release control should be provided on the outboard side of each folding seat back. If the seat back is split and only one seat back folds, only one release control is required on the outboard side.; e. MVSS No. 210 - Seat Belt Assembly Anchorages 1. We judge that the fastening strength of the seat belt anchorage wil change, depending on the shape of the eye bolt attaching the seat belt to the seat belt anchorage point.; If an anchorage is tested by using our designed seat belt assembly an the strength of the anchorage can be assured, we understand that the anchorage fully conforms to the standard, and also understand that it is not necessary to guarantee the owners of Mazda vehicles if they attach a seat bolt assembly other than the one designated by us. Is our interpretation correct?; We, of course, will specify in our Operation Manual that the seat bel assembly designated by our company must be used.; ANSWER: Under Paragraph S.5.1 of Federal Motor Vehicle Safety Standar No. 210, anchorages are to be tested by using a Type 1 or Type 2 seat belt assembly as defined in FMVSS No. 209. If you follow this procedure, using a belt which complies to No. 209, and your anchorages meet the requirements of Standard No. 210, then you are in compliance with this standard.<<<; I must point out that this Bureau does not issue approvals on items o equipment or on vehicle designs. 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 Standards.; Sincerely, H. M. Jacklin, Jr., Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam4879OpenMr. Danny J. Pugh Engineering Manager Special Service Vehicles Utilimaster Corporation 65266 State Road 19 P.O. Box 585 Wakarusa, IN 46573; Mr. Danny J. Pugh Engineering Manager Special Service Vehicles Utilimaster Corporation 65266 State Road 19 P.O. Box 585 Wakarusa IN 46573; Dear Mr. Pugh: This responds to your letter of April 15, 1991 regardin requirements for safety belts and door hardware in the prisoner area of police vehicles. Specifically, you asked if police vehicles are required to have seatbelts for prisoners, and if so, what type. You also asked if these vehicles are required to meet the door hardware requirements of Standard No. 206 for rear and side doors. All new vehicles, including police vehicles, are required to comply with all safety standards applicable to their type. Therefore, police vehicles, unless they are buses, are required to have safety belts at all designated seating positions when they are sold to the customer. Our December 13, 1990 letter to you regarding van conversions summarizes what type of safety belts are required depending on the seating position and vehicle type. In addition, police vehicles are required to comply with the requirements of Standard No. 206, if the vehicle is classified as a passenger car, a multipurpose passenger vehicle or a truck. You should note, however, that the requirements of Standard No. 206 do not apply to back doors, including car hatchbacks, van rear doors, and pickup truck tailgates. I hope you find this information helpful. If you have further questions, please contact Mary Versailles of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam0093OpenMr. B.A. Luff, General Manager, Lotus Vehicle Engineering, Division of Lotus Cars Limited, Wymondham 3411, Norwich 92W, England; Mr. B.A. Luff General Manager Lotus Vehicle Engineering Division of Lotus Cars Limited Wymondham 3411 Norwich 92W England; Dear Mr. Luff: Mr. Bridwell has asked that I reply to your letters dated November 1 and July 3 which ask if Motor Vehicle Safety Standard No. 201 requires your company's 'Elan Convertible' to have sun visors.; The National Highway Safety Bureau recognizes that the requirements fo every passenger car to have two sun visors of energy-absorbing material with mountings that have no rigid material edge radius of less than 0.125 if statically contactable by a 6.5 inch diameter head form, aay(sic) create a problem for manufacturers of certain types of vehicles. However, the requirement will, on balance, contribute to the safety of the general public.; Compliance with the requirement can and should be made in a manner s as to increase occupant protection.; Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel for Regulations |
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ID: aiam2554OpenMr. Michael Shillinger, AM General Corporation, 32500 Van Born Road, Wayne, MI 48148; Mr. Michael Shillinger AM General Corporation 32500 Van Born Road Wayne MI 48148; Dear Mr. Shillinger: This responds to your oral request of March 28, 1977, for clarificatio of the language of S5.4.1 of Standard No. 217, *Bus Window Retention and Release*. In particular, you ask whether the long side of a rectangular roof exit is required to be parallel to the center line of a bus.; S5.4.1 requires that an exit provide an opening large enough to admi unobstructed passage, keeping a major axis horizontal at all times, of an ellipsoid generated by rotating about its minor axis an ellipse having a major axis of 20 inches and a minor axis of 13 inches.' Further, S5.2.1 of the standard states that a roof exit shall meet these requirements when the bus is overturned on either side. The requirement that the major axis be kept horizontal while the bus is on its side means that the major axis, and therefore the long side of the rectangular roof exit, would be parallel to the center line or the side wall of a bus.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5291OpenLawrence F. Henneberger, Esq. Arent Fox Kintner Plotkin & Kahn 1050 Connecticut Avenue, NW Washington, DC 20036-5339; Lawrence F. Henneberger Esq. Arent Fox Kintner Plotkin & Kahn 1050 Connecticut Avenue NW Washington DC 20036-5339; Dear Mr. Henneberger: This responds to your letter in which you reques an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) 105, Hydraulic Brake Systems, on behalf of your client, MICO, Inc. I apologize for the delay in our response. You ask that the agency give you an interpretation that FMVSS 105 does not preclude the installation of MICO's product, an auxiliary hydraulic brake lock, under the circumstances you have described. As you note in your letter, NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with applicable safety standards. The following represents our opinion based on the facts provided in your letter. According to your letter, MICO's auxiliary hydraulic brake lock operates as follows. The device permits hydraulic system fluid to pass from the master cylinder to the brakes when the brake pedal is applied, thereby increasing hydraulic brake pressure. The device then blocks the return of the hydraulic fluid to the master cylinder when pressure is removed from the brake pedal. The device is not designed to be used when the vehicle is in motion, but only when the vehicle has been brought to a full stop, and the mechanical parking brake applied. At that point, the vehicle operator activates the auxiliary brake lock by means of a separate control switch. The device is deactivated prior to moving the vehicle. FMVSS 105 specifies requirements for hydraulic brake service brake and associated parking brake systems. The standard applies to vehicles with hydraulic service brake systems. In the case of an auxiliary hydraulic brake lock, there is no applicable standard for it as a separate item of motor vehicle equipment. However, since installation of the device requires cutting into a vehicle's braking system, it may affect a vehicle's compliance with safety standards. If MICO's auxiliary brake lock is installed as original equipment on new vehicles, the vehicle manufacturer would be required to certify that the entire brake system satisfies the requirements of FMVSS 105. If the device is added to a new motor vehicle prior to its first sale, the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. In particular, the vehicle would need to continue to comply with FMVSS 105. MICO, as the manufacturer of the device, would have no certification responsibilities. However, a vehicle manufacturer or alterer might require information from MICO in order to make its necessary certification. Much of the information that you provided to us in your request for an interpretation might be useful in this regard. Should the auxiliary brake lock be installed on a used vehicle by a manufacturer, distributor, dealer, or motor vehicle repair business, the installer would not have to attach a certification label. However, it would have to make sure that it did not knowingly render inoperative the compliance of the vehicle with any safety standard. I note that while we do not have any opinion about the safety of MICO's product, it is our understanding that certain vehicle manufacturers have stated that hydraulic brake locking devices should not be used on their vehicles. I enclose an example from a GMC service bulletin. MICO may wish to consult with these manufacturers concerning whether the use of its product in these vehicles would raise any safety concerns. Enclosed is an information sheet which identifies Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers. I note that the Safety Act's provisions concerning defects are applicable to motor vehicle equipment manufacturers even if their equipment is not covered by a safety standard. I hope this information has been helpful. If you have any further questions, please contact David Elias of my office at the above address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures; |
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ID: aiam0569OpenMr. K. Nakajima, Director/General Manager, Toyota Motor Company, Ltd., Lyndhurst Office Park, 1099 Wall Street West, Lyndhurst, NJ 07071; Mr. K. Nakajima Director/General Manager Toyota Motor Company Ltd. Lyndhurst Office Park 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima: This letter is in response to your inquiry of January 6, 1972 regarding the relationship of Standards No. 208 and No. 216.; You interpret Standard 216, paragraph *S3. Application*, which state that the Standard does not apply to passenger cars 'that conform to the rollover test requirements (S5.3) of Standard 208 by means that require no action by vehicle occupants,' as follows:; >>>1. From August 15, 1973, the effective date of Standard 216, t August 15, 1977, passenger cars are not required to meet Standard 216 if they conform to the 'first option' of Standard 208.; 2. For the period of August 15, 1973, through August 14, 1975 passenger cars which are designed to conform to the 'second' or proposed 'third' option of Standard 208 are not required to meet Standard 216 if they meet the rollover requirements (S5.3) by passive means (when tested under the applicable conditions of S8), even though in Standard 208 the rollover requirement is specified only for 'option 1.'<<<; These interpretations are correct. Please write if we can be of furthe assistance.; Sincerely yours, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2807OpenMs. Susan H. Soodek, 1025 Connecticut Avenue, N.W., Washington, DC 20036; Ms. Susan H. Soodek 1025 Connecticut Avenue N.W. Washington DC 20036; Dear Ms. Soodek: This responds to your recent letter asking whether Federal Safet Standard No. 205 specifies requirements limiting the reflectivity of glazing materials. You are concerned with the lack of uniformity in state laws that prohibit nontransparent or reflective windows in motor vehicles.; The stated purpose of Safety Standard No. 205, *Glazing Materials*, i to reduce injuries resulting from impact to glazing surfaces, to ensure a necessary degree of transparency in motor vehicle windows for driver visibility, and to minimize the possibility of occupants being thrown through the vehicle windows in collisions. The standard does not prohibit reflective glazing, nor does it specify requirements that would limit the degree of reflectivity of glazing materials.; Since reflectivity is not an aspect of performance governed by Federa safety standards, state laws concerning glazing reflectance would not be preempted by Standard No. 205. Safety Standard No. 205 does, however, specify requirements for the luminous transmittance of glazing materials for use in motor vehicles. Therefore, state laws prohibiting nontransparent windows would be preempted if they attempted to regulate the glazing manufacturer or the vehicle manufacturer (15 U.S.C. 1392(d)). State regulations applicable to the vehicle owner or user would not be preempted, on the other hand, since the Federal regulation is only applicable to the manufacturer. Therefore, a state law could prohibit the application of a nontransparent decal on a window by a vehicle owner, for example.; I am enclosing a copy of the California Highway Patrol petition fo rulemaking regarding glazing abrasion requirements and glazing reflectivity. A notice concerning this petition will be issued at some time in the near future.; I must point out that our statutory authority requires all safet standards to be reasonable, objective and to meet the need for motor vehicle safety. The agency cannot, therefore, regulate an aspect of motor vehicle performance or design if there is no data or evidence indicating that a safety problem exists.; I hope this has been responsive to your inquiry. Please contact Hug Oates of my office if you have any further questions.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1728OpenMr. David E. Martin, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Mr. David E. Martin General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Martin: This responds to General Motors' January 14, 1975, request fo confirmation that a Type II seat belt assembly demonstrated to Messrs. Carter, Detrick, Hofferberth, Burgett, Hitchcock, and Herlihy of the NHTSA on December 17, 1974, satisfies the requirements of S7.1.1 of Standard No. 208, *Occupant crash protection*, that the lap belt portion 'adjust by means of an emergency-locking or automatic-locking retractor.' You describe the seat belt assembly as of the singly retractor, continuous loop type, with a B-pillar-mounted 'window shade' emergency-locking retractor, and a one-way frictional 'D ring' buckle tongue which limits return of webbing to the lap belt portion from the torso portion when the belt assembly is in use. At the December 17 demonstration you specifically asked if the 'D ring' frictional characteristics satisfy the criterion established in a September 25, 1972, letter to Renault, Inc. (copy enclosed), that 'the friction in the buckle is low enough that the normal motion of the occupant against the shoulder belt cinches up the lap belt.'; Section S7.1.1 requires adjustment of the lap belt portion 'by means o an emergency-locking or automatic-locking retractor' and adjustment in most cases of the upper torso portion 'by means of an emergency-locking retractor.' The language permits some single retractor, continuous loop systems as long as the single retractor does 'automatically adjust' the tension of the lap belt portion to prevent excessive belt slack. Because of the submarining danger of a slack lap belt, the NHTSA has restricted the acceptability of continuous loop systems under S7.2.2 in two areas.; One restriction was set out in the Renault letter and it is the basi for your question whether the GM 'D ring' has a sufficiently low level of friction to qualify the lap portion as 'automatically adjustable.'; We would like to clarify that letter by emphasizing that, to conform t the requirements, the assembly must be *designed* by the manufacturer with a sufficiently low level of friction to qualify the lap portion as 'automatically adjustable.' THus it is the manufacturer who determines whether or not the particular belt is designed to satisfy the requirements of the standard. In your December 17 demonstration we saw no evidence of design deficiency in limited use of that continuous loop system.; The other restriction was set out in a March 9, 1973, letter to Genera Motors (copy enclosed). It limits the use of 'comfort clips' on the upper torso portion of continuous loop systems. The letter distinguishes continuous loop systems from systems that have separate lap and shoulder belt retractors. It concludes that 'a comfort clip would be acceptable under S7.1.1 of the standard, so long as the shoulder belt is otherwise capable of adjustment as required by S7.1.1'; This restriction has since been the subject of an NHTSA proposa (Docket 74-32, Notice 1) which would restrict the use of 'a device used to limit retractive action of an emergency-locking retractor for the comfort of the occupant' to seat belt assemblies that have 'an individually adjustable lap belt.' General Motors' response to that proposal and its anticipated use of a 'window shade' device in future continuous loop systems assume that NHTSA intends to permit 'belt tension relief' devices on all continuous loop systems. I would like to point out that this issue is outstanding in Docket 74-32.; Pursuant to your request for confidential treatment of this question o a new seat belt assembly, this letter will be made public only after the introduction of the new vehicle in question.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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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.