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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



Displaying 11191 - 11200 of 16517
Interpretations Date

ID: nht92-1.34

Open

DATE: December 8, 1992

FROM: George D. James, Jr. -- Safety Chairman, Unit 169 WBCCI

TO: Paul Jackson Rice -- Chief Counsel, U.S. Department of Transportation, NHTSA; Attention: Stephen P. Wood -- Assistant Chief Counsel for Rulemaking, U.S. Department of Transportation, NHTSA

TITLE: RE Tekonsha Electronic Brake Control ("Control")

ATTACHMT: Attached to letter dated 5-21-93 from John Womack to George D. James, Jr. (A41; Std. 108)

TEXT: Thank you for your 12/4/92 reply to my 10/24/92 letter objecting to your "approval" of this brake controller. Because your agency does not "approve", "endorse" or offer assurance of compliance of any M.V, equipment, I err in thinking you have "approved" these controllers.

I still believe that using trailer brakes without activating the STOP LIGHTS is an unsafe procedure AND you imply approval.

You state that "at this time we do not have any data indicating a real-world safety problem created by the use of the Tekonsha brake control".

What data do you need to realize that a rear end collision (or a following vehicle choosing to leave the road to avoid one) or chain-reaction collisions caused by a slowing or stopping vehicle WITHOUT STOP LIGHTS BEING ACTIVATED is not a "real world" safety problem?

How many thousands of such accidents have already been recorded? How many violation citations with or without penalties have been made because of inoperating stop lights?

Mr. Wood, I've just talked with the Macon County Sheriff's Department and the State Highway Patrol (North Carolina) and they both confirm that:

1. There'll be a lot more collisions on the highways if vehicles are permitted to run with non-operating stop lights, and

2. Don't get caught here with stop lights not working or you'll for sure be ticketed.

Now by George, you KNOW this is right. YOU DON'T NEED "MORE DATA"! HOW CAN YOU SAY YOUR AGENCY'S GOAL IS MINIMIZING DEATHS AND INJURIES ON THE HIGHWAYS, and still defend your decision re these new brake controllers? HOW CAN YOU SAY YOU NEED MORE DATA INDICATING A POTENTIAL PROBLEM?

ID: nht92-1.35

Open

DATE: 12/07/92

FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TO: MARK V. SCHWARTZ -- ACCOUNT EXECUTIVE, ENTRAN DEVICES, INC.

ATTACHMT: ATTACHED TO LETTER DATED 10-28-92 FROM MARK V. SCHWARTZ TO PAUL J. RICE (OCC 7927)

TEXT: This responds to your October 28, 1992 letter, asking me to reconsider my September 29, 1992 letter to you interpreting 49 CFR Part 572, Anthropomorphic Test Dummies. More specifically, my September 29, 1992 letter addressed the requirement in @ 572.36(g) that the thorax and knee impactor accelerometers in the Hybrid III test dummy "shall have the dimensions and characteristics of Endevco Model 7231c or equivalent."

You had asked if one of your company's accelerometer models would be deemed "equivalent," within the meaning of @ 572.36(g), to the specified make and model accelerometer. I stated that Part 572 sets forth the specifications with which test dummies must comply if those test dummies are to be used in this agency's compliance testing. I further stated that the agency has always used the specified make and model accelerometer in the compliance testing conducted to date. Thus, it has not been necessary for the agency to make any determination of which accelerometers, if any, are "equivalent" to the specified accelerometer for agency compliance testing purposes. Until the agency makes a determination about equivalent accelerometers, I indicated that the matter is one to be worked out between your company and prospective users of your company's accelerometers. I also indicated that NHTSA will not review the use of any particular accelerometers in certification testing, including your company's accelerometers, unless the test results indicate a problem or problems caused by those accelerometers.

In your October 28, 1992 follow-up letter, you expressed that you were "extremely disappointed" with my September 29 letter. You stated that "[though] your letter states that users of accelerometers are free to define equivalence, the reality is that they will take no unnecessary course of action that varies from your compliance testing." You said that you had spoken with "technical decision makers" at Chrysler, Ford, and GM and all three indicated that they would not use an accelerometer for development and certification work, when a different accelerometer must be used in NHTSA's compliance testing. Accordingly, you again asked that the agency state whether a model of accelerometer manufactured by Entran is equivalent to the make and model of accelerometer specified for use in compliance testing.

In order to make a determination of which accelerometer models are "equivalent" to the make and model of accelerometer currently specified for use in compliance testing, NHTSA must conduct an analysis to identify the attributes that will ensure that an accelerometer measures results in the relevant crash environment that are equivalent to the results that would be measured in that crash environment by the currently specified accelerometer. This analysis would require an expenditure of agency time and resources, although the amount of the expenditure is currently not known. These expenditures would not benefit the agency's compliance testing efforts, since the currently specified accelerometer is readily available, nor would the expenditures contribute generally toward the agency's safety mission. Accordingly, the agency cannot justify the expenditure of resources needed to make an analysis of the equivalence issue at this time.

However, accelerometer manufacturers and other interested parties are free to make their own analyses of equivalence, using their resources. The interested parties may present their analyses of equivalence to potential users of a non-specified accelerometer, in order to demonstrate to the potential user that the non-specified accelerometer will be found equivalent to the specified accelerometer when NHTSA makes its determination of equivalence. If the potential user is convinced by such demonstration, that party can then use the non-specified accelerometer in its testing.

In my previous letter to you, I stated that NHTSA will not review the use of any particular accelerometers in certification testing, unless the test results indicate a problem or problems caused by those accelerometers. This statement was included in that letter to make clear to all parties that the absence of a NHTSA determination of equivalence for a particular accelerometer model does not represent some sort of negative finding by the agency with respect to the performance or capabilities of that particular accelerometer. This statement has apparently served that purpose. For instance, it has come to our attention that Chrysler and General Motors have procured significant numbers of Entran accelerometers for use in vehicle crash tests. Thus, it appears that vehicle manufacturers and other potential users correctly understand the meaning of the current specification in Part 572 for one particular accelerometer model, and that the specification of one particular accelerometer model in Part 572 does not pose any insuperable obstacle to the use of other, non-specified accelerometer models for testing other than NHTSA's certification testing. There is, therefore, no compelling need for NHTSA to use its resources to conduct an analysis of accelerometer equivalence.

ID: nht92-1.36

Open

DATE: 12/07/92

FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TO: MARK W. RUSSO

COPYEE: MICHAEL F. HECKER -- MICHO INDUSTRIES

ATTACHMT: ATTACHED TO LETTER DATED 9-17-92 FROM MARK W. RUSSO TO WALTER MYERS (OCC 7817); ALSO ATTACHED TO LETTER DATED 7-14-92 FROM PAUL J. RICE TO MICHAEL F. HECKER (STD. 222)

TEXT: This responds to your letter to Walter Myers of this office regarding the applicability of Federal Motor Vehicle Safety Standard No. 222 to the R-Bar Passenger Restraint System and related issues. I note that on July 13, 1992, I sent you copies of five previous NHTSA letters which addressed the use of "safety bars" in school buses. In your new letter, you expressed a number of safety concerns about the R-Bar and asked whether there have been any further development at NHTSA regarding the R-Bar subject since May 14, 1992, the date of the most recent of the five letters I sent to you.

We have issued one additional letter concerning Standard No. 222 and the use of "safety bars" in school buses. The letter (copy enclosed) was sent to Mr. Michael F. Hecker of Micho Industries on July 14, 1992, and concerned how the R-Bar should be positioned during testing under Standard No. 222. As discussed in that letter, a school bus must meet the requirements of Standard No. 222 with a "safety bar" in every position at which it may be placed.

I also note that manufacturers of motor vehicles and motor vehicle equipment are subject to the defect provisions of the National Traffic and Motor Vehicle Safety Act. If data indicated that devices such as "safety bars" were exposing occupants to an unreasonable risk of injury, such as by excessive abdominal or leg loading during a crash, the agency might conduct a defect investigation which could lead to a safety recall.

If you have any further questions or need any additional information, feel free to contact Mr. Myers at this address or at (202) 366-2992.

ID: nht92-1.37

Open

DATE: 12/07/92

FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TO: KENNETH W. WEBSTER II -- PROJECT ENGINEER, TRANSPORTATION RESEARCH CENTER INC.

ATTACHMT: ATTACHED TO LETTER DATED 10-15-92 FROM KENNETH W. WEBSTER, II TO PAUL J. RICE (OCC 7872)

TEXT: This responds to your letter to me dated October 15, 1992, seeking an interpretation of Standard No. 110, Tire Selection and Rims - Passenger Cars (49 CFR @ 571.110). More specifically, you were interested in a clarification of the test conditions for determining compliance with the requirement in S4.4.1(b) of Standard No. 110, which provides that each rim on a new passenger car shall "[in] the event of a rapid loss of inflation pressure with the vehicle traveling in a straight line at a speed of 60 miles per hour, retain the deflated tire until the vehicle can be stopped with a controlled braking application."

In your letter, supplemented by your November 2, 1992 telephone conversation with Mr. Walter Myers of my staff, you explained that your company, Transportation Research Center Inc., has conducted tests on a passenger car that is to be marketed in the United States. Two tire and rim configurations are available with the car: a steel rim mounted with a Goodyear tire, and a decorative aluminum rim mounted with a Michelin tire. I understand these tires and rims to be the same size and to have the same nominal dimensions. In addition, I understand the tires to be of the same type and construction. You stated that you tested both tires on both rims in accordance with this agency's test procedure for determining compliance with Standard No. 110 (TP-110-02). The tire/rim combinations being tested were mounted on the left front and right rear positions, but in some cases tires made by a different manufacturer, but of the same size, type, and composition as the tires at the test positions, were mounted at the other wheel positions. You asked whether all tire and rim configurations on the vehicle for testing under S4.4.1(b) of Standard No. 110 must be made by the same manufacturer and otherwise be exactly alike. The short answer to your question is no.

Before discussing your specific question, however, I would like to explain how the National Highway Traffic Safety Administration (NHTSA) determines compliance in cases where a standard does not specify a particular adjustment position or test condition. In issuing Federal motor vehicle safety standards, NHTSA endeavors to specify all relevant adjustment positions or test conditions to ensure that our standards are objective and practicable. As a practical matter, however, it is not always possible to anticipate every conceivable adjustment position or test condition.

In those cases where a standard does not specify a particular adjustment or test condition, we consider several factors in interpreting the standard. We begin with the presumption that the requirements of the standard must be met regardless of such adjustment position or test condition, because the language of the standard does not limit the applicability of its requirements to any such adjustment position or test condition. NHTSA then examines the language of the standard as a whole and its purposes, to see if the language of the standard or its purposes indicate an implicit intent to limit such adjustment positions or test conditions and what limitation was intended.

Applying this approach in response to your inquiry, we believe that the language and the purpose of S4.4.1(b) of Standard 110 are clear, namely that the rim must retain the deflated tire until the vehicle can be stopped with a controlled braking application. The focus of the test is the ability of the rim to retain the deflated tire without unduly affecting the vehicle dynamics. Hence, the only limitation on the tire/rim combinations at the other wheel positions would be that those other tire/rim combinations that are not being tested must not unduly affect the dynamics of the vehicle (and, hence, the test result) when combined with the tire/rim combination being tested. Thus, unless testing the compact spare tire provided by the vehicle manufacturer, NHTSA would conduct its compliance testing for S4.4.1(b) of Standard 110 using tires of the same size, type (all-season, mud/snow, etc.), and construction (radial, bias-belted, etc.) as the tire being tested on the other three wheel positions. NHTSA would not, however, limit its testing to using only tires made by the same manufacturer as the tire being tested at the other three wheel positions.

I hope this information is helpful. If you have any further questions, please feel free to contact Mr. Myers at this address or at (202) 366-2992.

ID: nht92-1.38

Open

DATE: 12/07/92

FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TO: RICHARD HORIAN -- PRESIDENT, WOODLEAF CORP.

ATTACHMT: ATTACHED TO LETTER DATED 11-6-92 FROM RICHARD HORIAN TO PAUL J. RICE (OCC 7980)

TEXT: This responds to your two letters of November 6, 1992, with respect to the allowability under Federal regulations of the "Sudden Brake Indicator Hazard Light." As you describe it, "when a driver engages in hard braking, a circuit activates a separate lighting system to warn other drivers to pay special attention to a potentially hazardous situation."

This system will not utilize any of the existing rear lights on a vehicle, and will consist of a single lamp or pair of lamps, either mounted separately, or in the same housing as the center high-mounted stop lamp. The system will be red or amber in color, and either steady burning or flashing. The system is activated only when a predetermined threshold of pressure is reached upon depression of the brake pedal.

Supplementary lighting systems such as the one you have described are permissible as original motor vehicle equipment under Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment if they do not impair the effectiveness of the lighting systems required by the standard, or if there is no provision of the standard that affects them. Paragraph S5.4 of Standard No. 108 specifically prohibits the physical combination of the center highmounted stop lamp with any other lamp or reflective device, thus your system could not be used in a common housing with the center light (see copy of enclosed letter to Mr. S. Suzuki on this subject). However, if the system is mounted separately, under the circumstances you have presented, we do not believe that there would be any direct impairment of the required rear lights, or indirect impairment such as might be created when confusion may result upon simultaneous operation of the supplementary light and any required light.

As the letter to Mr. Suzuki indicates, passenger cars manufactured before September 1, 1985, were not required to be equipped with the center lamp. This means that your light could be combined in the same housing as a center lamp intended for installation on vehicles manufactured before September 1, 1985, but it could not be part of a replacement center lamp intended for use on vehicles manufactured subsequently. In addition, with the exception just noted, installation of the system on a vehicle in use would not appear to affect the safety functioning of any safety system necessary for continued conformance of the vehicle, it would appear that your system is acceptable for sale and installation in the aftermarket as well. However, the individual States have the authority to regulate lamps for vehicles in use, and we suggest that you contact the American Association of Motor Vehicle Administrators (AAMVA) for an opinion as to whether the system is permissible under State laws. AAMVA's address is 4600 Wilson Boulevard, Arlington, Va. 22203.

ID: nht92-1.39

Open

DATE: 12/07/92

FROM: RICHARD LANGLAIS -- PRELCO, INC.

TO: MARVIN SHAW

TITLE: FVMSS 205

ATTACHMT: ATTACHED TO LETTER DATED 2-23-93 FROM JOHN WOMACK TO RICHARD LANGLAIS (A40; STD 205; PART SS2); ALSO ATTACHED TO LETTER DATED 11-26-91 FROM KATHLEEN DEMETER TO RICHARD LANGLAIS

TEXT: Last year, I received the information regarding the procedure to follow in order to get a D.O.T. number (I have enclosed a copy).

Would it be possible for you to give me more details about items 5, 6 and 7? Who can be our agent? Do you know some agents or firms which are specialized in this kind of service?

I would appreciate if you could get back to me at your earliest convenience.

Thanking you in advance for your collaboration, I remain,

ID: nht92-1.4

Open

DATE: 12/29/92

FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TO: LEO WENSTRUP -- MANAGER - TECHNICAL SERVICES, EATON CORPORATION, AXLE AND BRAKE DIVISION

ATTACHMT: ATTACHED TO LETTER DATED 11-3-92 FROM LEO WENSTRUP TO NHTSA OFFICE OF CHIEF COUNSEL (OCC 7963)

TEXT: This responds to your letter asking about the dynamometer requirements of Federal Motor Vehicle Safety Standard No. 121, Air Brake Systems (49 CFR 571.121). You explained that you have experienced problems in conducting certification testing of brake lining for vehicles in a city refuse fleet. Specifically, you stated that while the fade portion of the dynamometer test specifies decelerations from 50 miles per hour (mph) to 15 mph, the trucks in question have a maximum vehicle speed governed to 45 mph. You asked at what speed should the fade portion of the test be conducted given that these trucks are governed to a lower speed. I am pleased to have this opportunity to explain our regulations to you.

Some background information on Federal motor vehicle safety laws and regulations may be helpful. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. @ 1381 et seq., Safety Act) authorizes this agency to issue safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards.

Manufacturers must have some basis for their certification that a product complies with all applicable safety standards. This does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations. Whatever the basis for certification, however, the manufacturer must certify that the product complies with a standard as it is written, i.e., that the vehicle will pass all applicable requirements if it is tested exactly according to the standard's test conditions and other specifications.

Standard No. 121's dynamometer test requirements are set forth in section S5.4. That section specifies that brake assemblies must meet the requirements of S5.4.1 (brake retardation force--relevant only to towed vehicles), S5.4.2 (brake power), and S5.4.3 (brake recovery), under the conditions of S6.2. The purpose of the dynamometer test requirements is to help ensure that brakes retain adequate stopping capacity during and after exposure to conditions caused by prolonged or severe use, such as long, downhill driving. In particular, the specified decelerations are designed to heat the brakes to simulate such severe driving conditions.

In conducting a compliance test, NHTSA would follow the procedures set forth in Standard No. 121. The standard expressly provides that decelerations are made from 50 mph to 15 mph in the dynamometer tests. See, for example, S5.4.2 and S5.4.2.1. Nothing in Standard No. 121 specifies an exception for vehicles with a maximum speed below 50 mph. Moreover, since the tests in question are dynamometer tests and not road tests, there would be no difficulty in conducting the tests at a speed higher than the vehicle's maximum speed.

I note that this opinion assumes that Standard No. 121 applies to the vehicles in question. Certain vehicles with slow maximum speeds are excluded from the standard's coverage. See S3. However, these exclusions do not appear to apply to the refuse trucks in question.

Your letter appears to imply that Standard No. 121's dynamometer tests are inappropriate for vehicles which have a maximum speed governed to less than 50 mph. We note, however, that a governor set at 45 mph does not prohibit a vehicle from achieving speeds greater than 50 mph in certain situations such as driving downhill. In addition, as indicated above, the specified decelerations are designed to heat the brakes to simulate the severe driving conditions caused by prolonged and severe use and long downhill driving. The same degree of heating can occur at speeds below 50 mph. Therefore, we believe that the specified tests are appropriate for vehicles with a maximum speed governed to below 50 mph.

If you have any further questions, please feel free to call Mr. Marvin Shaw of my staff at (202) 366-2992.

ID: nht92-1.40

Open

DATE: 12/07/92

FROM: WILLIAM R. WILLEN -- MANAGING COUNSEL, PRODUCT LEGAL GROUP, AMERICAN HONDA MOTOR CO., INC.

TO: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 2-24-93 FROM JOHN WOMACV TO WILLIAM R. WILLEN (A40; PART 571.3)

TEXT: This is to request your confirmation of our interpretation regarding the definition of "designated seating position" in 49 CFR Section 571.3 as it applies to a proposed Honda design. The Honda design is similar to one for which NHTSA provided an interpretation to Jguar Rover Triumph in July, 1980. The hip room is 44.2 inches over the length of our seat, and the seat width is only 39 inches. The seat is flat and does not have stiff inboard seat belt receptacles. (Please see the attached sketches).

We believe that, under the above mentioned definition, two designated seating positions would be required for this design and we would like to receive your confirmation. We also reguest your answers to the following questions regarding the determination of designated seating positions.

1. With regard to this proposed design, is the seat width dimension the key factor in determining the number of designated seating positions? If the seat width was 40 or 42 or 44 inches instead of 39 inches would your interpretation be different?

2. Please explain how you would measure hip room in the examples shown below where the seat is installed in a wider vehicle.

(a) The seat is located close to one side with space for passenger access on the other side.

(GRAPHICS OMITTED)

(b) The seat is located in the middle of the vehicle with space on each side.

(GRAPHICS OMITTED)

(c) Note that the seat does not have armrests in the sketches. Would the answer be different if armrests were provided? Would it also make a difference if the armrests were fixed or if they were able to swing up beside the seatback to provide easy access?

ID: nht92-1.41

Open

DATE: December 7, 1992

FROM: W. C. Burke -- Captain, Commander, Commercial and Technical Services Section

TO: Paul Rice -- Chief Counsel, NHTSA

TITLE: File No.: 62.A8383.A9181.5242C

ATTACHMT: Attached to letter dated 3-31-93 from John Womack to W. C. Burke (A41; Std. 205)

TEXT: Recently, Mr. Greg Bragg from our California Highway Patrol (CHP) Commercial and Technical Services section spoke with Mr. Marvin Shore and Mr. Clark Harper of your administration regarding the marking requirements of safety glazing installed in motor vehicles.

The specific issue they talked about was whether or not a glass installer replacing glass in a motor vehicle according to Federal Motor Vehicle Safety Standard (FMVSS) 205 is required to mark the glazing. FMVSS 205, S6.4 states "Each manufacturer or distributor who cuts a section of glazing material to which this standard applies, for use in a motor vehicle or camper, shall mark that material in accordance with section 6 of ANS Z26." According to the definitions contained in the National Traffic and Motor Vehicle Safety Act of 1966, an installer replacing glass in a motor vehicle would be a dealer and would, therefore, be exempt from the marking requirements.

We are inquiring about this matter because California has adopted FMVSS 205 and some of our CHP personnel have found school buses with replacement glass that is not marked. We have subsequently taken law enforcement action against these school districts. It has been our longtime understanding that all glass installed in a motor vehicle must be marked. However, after careful examination of the wording contained in both the FMVSS 205 and the Safety Act of 1966, it appears that the installer of replacement glass does not have to mark the glazing material and that our past interpretation of this Federal Standard may be in need of further review.

We, therefore, request a written interpretation from you on whether or not FMVSS 205 requires an installer (or dealer) who cuts sections of glass from a larger, marked section to mark each individual smaller section (if not already marked) prior to installing them as replacement windows.

Your immediate response to this question is greatly appreciated. If you have any questions regarding this matter please contact either Mr. Greg Bragg or Mr. Kyle Larsen of our Commercial and Technical Services Section at (916) 445-1865.

ID: nht92-1.42

Open

DATE: 12/04/92

FROM: STEPHEN P. WOOD -- ASSISTANT CHIEF COUNSEL FOR RULEMAKING, NHTSA

TO: GEORGE D. JAMES, JR. -- SAFETY CHAIRMAN, UNIT 169 WBCCI

ATTACHMT: ATTACHED TO LETTER DATED 10-24-92 FROM GEORGE D. JAMES, JR. TO PAUL J. RICE (OCC 7931)

TEXT: This responds to your letter of October 24, 1992, with respect to the Tekonsha electronic brake control. You believe that this agency has "approved" this brake control. Based on your experience towing a travel trailer, you expressed concern about the safety of these particular electronic brake controllers when in service on the public roads, because the stop lamps on the towed vehicle are not activated when the electronic brake control is used to apply the trailer's service brakes. You asked us to review our thinking and "rewrite the specs on this matter."

Let me begin by emphasizing that this agency has no authority to "approve," endorse, or offer assurances of compliance to any items of motor vehicle equipment. All that our letters of interpretation purport to do is to answer questions from manufacturers and other members of the public as to whether the manufacture, sale, and/or installation of equipment is permissible under applicable Federal laws and regulations. Our letter of April 3, 1992, to Echlin, Tekonsha's manufacturer, which you quote at one point, was a letter of interpretation, which concluded that "it now appears that the sale of the [Tekonsha] Control is not in violation of the National Traffic and Motor Vehicle Safety Act." This letter and conclusion can in no way be read as "approving," endorsing, or recommending the use of the Tekonsha system.

At this time, we do not have, nor are we aware of, any data indicating that there is a real-world safety problem created by use of the Tekonsha brake control. Hence, we have no reason to change the conclusion announced in the April 3 letter to Echlin about the legality of the Tekonsha control. We would be willing to review this matter again if data become available indicating a potential problem. Thus, if you or any member of your organization learns of any specific safety problems that have arisen for vehicles equipped with the Tekonsha control, please let us know.

I appreciate your interest in highway safety. It is only through the concern and support of citizens like yourself that this agency can achieve its goal of minimizing deaths and injuries on this nation's highways. Thank you for taking the time to let us know your thoughts on this matter.

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.

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