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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 12671 - 12680 of 16510
Interpretations Date
 search results table

ID: 8517a

Open

Mr. Lawrence Hufstedler
Mr. Raymond Kesler
Kesler Research Enterprises, LTD.
5508 Cahuenga Boulevard
North Hollywood, CA 91601

Dear Messrs. Hufstedler and Kesler:

This responds to your letter inquiring about the field-of-view requirements in Federal Motor Vehicle Safety Standard No. 111, Rearview Mirrors (49 CFR 571.111; copy enclosed) applicable to what you refer to as "passenger vehicles" weighing under 10,000 pounds. You requested a written interpretation explaining the Standard's requirements in situations where such vehicles have a left side and an interior mirror that comply with the field-of-view requirement. In particular, you wanted confirmation that in such situations a manufacturer may equip a vehicle's passenger side with any supplemental mirror or no mirror at all. You also asked whether the vehicle owner may equip a vehicle in this manner.

I am pleased to have this opportunity to explain our regulations to you. Along with a copy of Standard No. 111, I am enclosing the final rule that states the agency's decision to permit the use of convex mirrors on the exterior passenger side of passenger cars. (47 FR 38698, September 2, 1982). This notice explains the agency's regulations applicable to such convex mirrors in various situations.

By way of background, NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act) to issue Federal motor vehicle safety standards (FMVSS's) that set performance requirements for new motor vehicles and new items of motor vehicle equipment. NHTSA is not authorized to certify or approve motor vehicles or motor vehicle equipment for compliance with the FMVSS's. Instead, under the Safety Act, each manufacturer of a motor vehicle or item of motor vehicle equipment is responsible for certifying that its products meet all applicable safety standards.

NHTSA issued Standard No. 111 to establish performance requirements for mirrors installed in each new vehicle. Section S5 of Standard No. 111 specifies the requirements applicable to mirrors installed on passenger cars. S5 requires that passenger cars be equipped with an inside rearview mirror of unit magnification and a driver's side outside rearview mirror of unit magnification that provide the field-of-view specified in S5.1.1. If the inside rearview mirror meets the field-of-view requirements of S5.1.1, then a mirror on the passenger side is not required. Please be aware that in such a situation a manufacturer could voluntarily install any type of exterior passenger side mirror, which the agency would permit as a supplemental mirror.

If the inside rearview mirror of a passenger car does not meet the field-of-view requirements of S5.1.1, then a mirror of unit magnification or a convex mirror must be installed on the passenger side. If a convex mirror is installed on the passenger side to meet the field-of-view requirements, then that convex mirror must meet certain additional requirements that are set forth in section S5.4. These additional requirements address the convex mirror's permissible radius of curvature and an informational message that must be marked onto the mirror.

Section S6 specifies the requirements applicable to mirrors installed on multipurpose passenger vehicles (MPV's), trucks, and buses other than school buses, with a GVWR of 10,000 pounds or less. Such vehicles would comply with the standard if they are equipped with mirrors that conform to the requirements (expressed in the previous two paragraphs) that are applicable to passenger cars. Alternatively, MPV's, trucks and buses would comply with the standard if they are equipped with outside mirrors of unit magnification, each with not less than 19.5 square inches of reflective surface, on both sides of the vehicle.

Please note that the requirements of Standard No. 111 apply to new, completed vehicles and do not apply to mirrors installed as aftermarket equipment. The only limitation on aftermarket installations is set forth in section 108(a)(2)(A) of the Safety Act, which prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from knowingly rendering inoperative any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable safety standard. The rearview mirror system in a vehicle is a device installed in compliance with an applicable safety standard. If the installation of an aftermarket mirror system resulted in a vehicle no longer complying with Standard No. 111, a manufacturer, distributor, dealer, or motor vehicle repair business performing the work would have rendered inoperative a device (i.e., the mirror system) installed in the vehicle in compliance with Standard No. 111, in violation of 108(a)(2)(A).

In addition to the foregoing, you should be aware that manufacturers of motor vehicle equipment, such as vehicle mirrors, are subject to the requirements in 151-159 of the Safety Act concerning the recall and remedy of products with defects relating to motor vehicle safety. If you or NHTSA determines that a safety defect exists, you must notify purchasers of your product and remedy the problem free of charge. (Note that this responsibility is borne by the vehicle manufacturer in cases in which the mirror is installed on a new vehicle by or with the express authorization of that vehicle manufacturer.) Any manufacturer that fails to provide notification of or remedy for a defect may be subject to a civil penalty of up to $1,000 per violation.

Please note that the Safety Act does not establish any limitations on an individual vehicle owner's ability to alter his or her own vehicle. Under Federal law, individual vehicle owners can install any mirror system they want on their own vehicles, regardless of whether that mirror system renders inoperative the vehicle's compliance with the requirements of Standard No. 111. However, NHTSA encourages vehicle owners not to tamper with vehicle safety equipment if the modification would degrade the safety of the vehicle.

I hope this information is helpful. Please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information.

Sincerely,

John Womack Acting Chief Counsel

Enclosure ref:111#VSA d:4/27/93

1993

ID: 8529

Open

Mr. Bob Davis
Quality Control Manager
Horton Emergency Vehicles
500 Industrial Mile Road
Columbus, OH 43228

Dear Mr. Davis:

This is in response to your letter of April 13, 1993, requesting an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 206 as it affects the rear doors of ambulances that your company manufactures. I apologize for the delay in responding.

You state that your ambulances have two rear doors, and that each has locking mechanisms that can be operated both from the outside and inside of the doors. Your specific question is whether you can eliminate the inside locking mechanism on one of the rear doors without violating Standard No. 206. The language in S4.1.3 of Standard No. 206 that you noted in your letter (i.e., "Each door shall be equipped with a locking mechanism with an operating means in the interior of the vehicle.") refers to side doors, but not to rear doors. Thus, your company's ambulances need not be equipped with locking mechanisms on each rear door.

I hope this information has been helpful. If you have any further questions feel free to contact David Elias of my office at the above address or by phone at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

ref:206 d: 7/27/93

1993

ID: 8539

Open

AIR MAIL
Mr. T. Kouchi
Director
Stanley Electric Co., Ltd.
2-9-13, Nakameguro, Meguro-ku
Tokyo 153, Japan

Dear Mr. Kouchi:

This responds to your letter of April 2, 1993, to Paul Jackson Rice, the former Chief Counsel of this agency.

You refer to Mr. Rice's letter of December 30, 1992, which you interpret as saying that "any device that contains more than three lighted sections, or LEDs, need only comply with the requirements prescribed for three lighted sections." You consider "that the lamps having three lighted sections described in the attached drawing No. 1 & No. 2 need only comply with the photometric requirements prescribed for three lighted sections." You ask "if our idea is appropriate."

We confirm your interpretation with respect to drawing No. 1, which appears essentially the same as covered by Mr. Rice's interpretation. With respect to drawing No. 2, this lamp appears to be composed of a panel of LEDs flanked by two incandescent bulbs. When the LED panel alone is operated, or when it is operated in conjunction with either one or both of the incandescent bulbs the requirements applicable to three lighted sections will apply. However, each bulb is regarded as being a single light source so that if the bulbs are operated individually, only the requirements for single lighted sections apply. If the bulbs are operated simultaneously to perform the same function, the requirements for two lighted sections apply. However, if the bulbs are operated simultaneously to perform different functions, the single lighted section requirements apply and all other requirements such as contrast ratios (e.g., the l:5 for tail and stop lamps) must be met.

Sincerely,

John Womack Acting Chief Counsel ref:108 d:4/23/93

1993

ID: 8546ar

Open

Mr. Dale Moore, CIC
Hagan Hamilton Insurance
and Financial Services
448 South Baker
Post Office Box 847
McMinnville, OR 97128

Dear Mr. Moore:

This responds to your letter addressed to Walter Myers of this office in which you asked whether 15-passenger vans used by Linfield College to transport high school-age students to the college must comply with the Federal motor vehicle safety standards applicable to school buses. You explained in your letter and its enclosure that Linfield College sponsors an "Upward Bound" program, in which selected high school-age students from disadvantaged families are transported to the college campus for academic tutoring and other activities, including field trips, counseling, etc. You have been advised that the college's 15-passenger vans "may have to meet federal requirements in order to be leased or purchased from an automobile dealer."

Let me begin by stating that the National Highway Traffic Safety Administration's (NHTSA's) requirements for new school buses regulate the manufacture and sale or lease of new vehicles used for transporting students. The Federal requirements do not, however, regulate what bus may be used for particular student transportation purposes. The requirements that apply to the use of school vehicles are set by the State. Thus, if there are regulations about what buses an Oregon college must use to transport Oregon high school students, such regulations are administered by the State of Oregon, not the Federal government.

Some background information on our requirements might be helpful to your inquiry. The National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1381 to 1431, as amended (Safety Act) authorizes NHTSA to issue Federal motor vehicle safety standards (FMVSSs) applicable to the manufacture and sale of new motor vehicles, including school buses. The Safety Act defines a school bus as "a passenger motor vehicle which is designed to carry more than 10 passengers in addition to the driver, and which . . . is likely to be significantly used for the purpose of transporting primary, preprimary, or secondary school students to or from such schools or events related to such schools."

It is a violation of the Safety Act for any person to sell or lease any new motor vehicle as a school bus that does not comply with all Federal school bus safety standards. It is not a violation of Federal law, however, to sell any noncomplying used vehicle as a school bus, even if the seller knows the vehicle will be significantly used as a school bus. Similarly, it is not a violation of Federal law to use a noncomplying vehicle to transport school children. As noted above, that is because individual states, not the Federal government, regulate the use of motor vehicles.

In the situation described in your letter, several issues must be addressed to determine whether the vans are subject to our school bus safety standards. The first issue is whether the vans are "buses." Since the vans are designed to carry more than 10 persons, the answer to that question is yes. The second issue is whether Upward Bound activities are considered "school related events." Although Oregon may have a specific definition of "school related event" for the purpose of determining whether Linfield College must use certified school buses, with regard to Federal law, we conclude the answer is yes. That is, if a new bus were sold or leased to the college, we would consider the new vehicle as being sold or leased for a school related event. The goal of Upward Bound is to prepare the participating students for post-secondary education. That is also, of course, one of the goals of the secondary schools in the program. Your enclosure states that Upward Bound staff "visit each high school on a weekly basis doing counseling and follow-up work with each student." These regular ongoing visits could not happen without the cooperation of the secondary schools in the program. Accordingly, it appears to us that the Upward Bound program is an "event related to" the secondary schools concerned, within the meaning of the Safety Act.

The final issue is whether transporting Upward Bound students constitutes a significant use for the vans. Linfield College need not purchase certified new school buses for its general purpose vehicles, even though such vehicles may be used occasionally to transport Upward Bound students. On the other hand, if Linfield College purchases or leases the vans knowing that they will be significantly used to transport Upward Bound students, the seller who knows of such anticipated use must sell only properly certified school buses.

For information regarding state requirements on the use of school buses, you may contact Mr. Donald Forbes, 135 Transportation Building, Salem, OR 97310, telephone (503) 378- 6388.

I hope this information is helpful to you.

Sincerely,

John Womack Acting Chief Counsel

ref:#571#VSA d:8/2/93

1993

ID: 8557

Open

Mr. Jim Keizer
1504 Locust Street
Hull, IA 51239

Dear Mr. Keizer:

This responds to your letter of April 13, 1993, requesting information on the legal responsibilities of businesses that repack or replace air bags in automobiles.

I am enclosing copies of five letters which address various issues related to replacement or repair of air bags. The January 19, 1990, letter to Ms. Linda L. Conrad addresses the issue of possible legal obligations to repair a deployed air bag following a collision. The May 13, 1991, and June 11, 1991, letters to Mr. Stephen Mamakas address issues specifically related to the repair of deployed air bags. The March 26, 1993, letters to Mr. Steven C. Friedman and Mr. Jay Lee address issues related to retrofit or replacement air bags.

I have also enclosed an information sheet that identifies relevant Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers, and explains how to obtain copies of these materials.

I hope you find this information 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,

John Womack Acting Chief Counsel

Enclosures

ref:208 d:5/6/93

1993

ID: 8559a

Open

Mr. Lanny Kness
Coach Design Engineer
Chance Coach, Inc.
4219 Irving, Box 12328
Wichita, KS 67277-2328

Dear Mr. Kness:

This responds to your request for an interpretation of two sections of Federal Motor Vehicle Safety Standard (FMVSS) No. 101, Controls and displays (49 CFR 571.101). You ask whether S5.1 requires a turn signal control to be hand operated. As explained below, the answer is no. You also ask whether S5.3's illumination requirements can be met by two different means: reflected light, and an overhead light. The answer is no.

By way of background information, the National Highway Traffic Safety Administration (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 motor vehicles or equipment comply with applicable safety standards. The following represents our opinion based on the facts provided in your letter.

Your first question asks whether S5.1 requires a turn signal control to be hand operated. S5.1 specifies location requirements for each control listed in S5.1 "that is furnished." S5.1 does not require manufacturers to furnish any control, such as a hand-operated turn signal control, or prohibit manufacturers from providing an unlisted control, such as a foot-operated turn signal control. While FMVSS No. 108, Lamps, reflective devices, and associated equipment (49 CFR 571.108) specifies the "turn signal operating unit" as required equipment, it does not specify that the unit be hand operated. (See S5.1.1 and Table I of FMVSS No. 108.)

Your second question asks whether the following proposed method of illuminating the windshield wiper/washer control complies with S5.3.3 of Standard No. 101. You state that the wiper/washer control is located on the dashboard and at night, the "control knob's identification" can be barely seen from indirect lighting coming from other controls and displays. The wiper washer control would become "very discernible" by turning on an "overhead driver's controlled light."

For the following reasons, the above described method of illuminating the wiper/washer control would not comply with Standard No. 101. S5.3.3(a) requires means to be provided to make controls visible to the driver under all driving conditions. S5.3.3(b) states that "the means" (emphasis added) for providing the required visibility:

(1) Shall be adjustable, except as provided in S5.3.3(d), to provide at least two levels of brightness, one of which is barely discernible to a driver who has adapted to dark ambient roadway conditions.

S5.3.3(b) therefore requires that a single control (i.e., "the means") be adjustable to provide at least two levels of brightness. Under your proposal, however, two different means must be used to provide two levels of brightness. The overhead driver's light would provide one level of brightness, that makes the control "very discernible." The other level of brightness (one barely discernible to the driver) is provided from reflected light given off by other controls and displays located on the dashboard. Since no single "means" that you propose for illumination would be adjustable to provide at least two levels of brightness, your proposal would not comply with S5.3.3 of Standard No. 101.

I hope that this information is useful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

ref:101#108 d:7/7/93

1993

ID: 8578

Open

Mr. Patrick P. Radice
Director of Operations
Electronics Division
Tridon
101 Evergreen Drive
Springfield, TN 37172

Dear Mr. Radice:

We have received your undated letter with respect to certification of aftermarket flashers.

You understand that manufacturers of aftermarket turn signal flashers and hazard warning signal flashers must certify that the flashers comply with the applicable requirements of Federal Motor Vehicle Safety Standard No. 108 prior to sale. However, when a vehicle is equipped with a combination turn signal/hazard warning signal flasher, you ask whether the manufacturer of the replacement flasher must certify compliance with requirements for both flashers, or can certify the flasher to "meet either the turn signal flasher or hazard warning signal flasher of FMVSS-108 but not both?"

Paragraph S5.8.1 (formerly S5.7.1) of Standard No. 108 requires that each item of lighting equipment manufactured to replace any item of lighting equipment on any vehicle to which Standard No. 108 applies shall be designed to conform to Standard No. 108. Therefore, a combination turn signal/hazard warning signal flasher that is manufactured to replace a combination turn signal/hazard warning signal flasher must be designed to conform to requirements applicable to both turn signal flashers and hazard warning signal flashers.

Paragraph S5.8.2 permits replacement lighting equipment to be labelled with the symbol DOT, constituting a certification of compliance to applicable Federal motor vehicle safety standards (although the manufacturer may certify by a label or tag affixed to the flasher or the container in which it is shipped). The "applicable Federal motor vehicle safety standards" for a combination turn signal/hazard warning signal flasher are those portions of Standard No. 108 that specify requirements for turn signal flashers and hazard warning signal flashers. The manufacturer's certification must therefore cover both.

I hope this explains the matter for you.

Sincerely,

John Womack Acting Chief Counsel ref:108 d:4/5/93 NCC-20 ZTVinson:mar:4/26/93:62992:OCC 8578 cc: NCC-0l Subj/Chron ZTVinson Interps/.Std. 108 8578; ztv; U:\ncc20\interp\108\8578.ztv

1993

ID: 8589

Open

Dr. Thomas Lckemeyer
Dept VER/LB
SWF Auto-Electric GmbH

FAX 07142/73 28 95

Dear Dr. Lckemeyer:

As you have requested, we are responding by FAX to your letter of April 28, 1993, to Taylor Vinson of this Office. You have asked two questions with respect to the acceptability of a multiple rear turn signal lamp under Federal Motor Vehicle Safety Standard No. 108, and have enclosed a sketch of the lamp.

Your first question is:

"Is it allowed to split the turn signal lamp in two parts with the dimensions given in the sketch . . . where the bigger part (4.5 sq. in.) is on the body of the car. The distance does not exceed 22 in."

Your question indicates that the turn signal lamp array of two lamps that is illustrated in the sketch is intended for installation on passenger cars or other vehicles whose overall width is less than 80 inches. Standard No. 108 incorporates by reference the SAE standard applicable to such vehicles, J588 NOV84. Paragraph 5.1.5.2 of SAE J588 NOV84 permits the use of multiple rear turn signal lamps to meet the photometric requirements of Standard No. 108.

When multiple lamps are used to meet the photometric requirements of a rear turn signal lamp, paragraph 5.3.3 of SAE J588 NOV84 requires that the functional lighted lens area of each lamp shall be at least 22 sq. cm, provided the combined area is at least 37.5 sq. cm. Your sketch shows that the functional lighted lens area of one lamp is 23 sq. cm, and of the other, 30 sq. cm, with a combined area of 53 sq. cm. Therefore, Standard No. 108 permits you to use the turn signal lamp array shown in your sketch. Your second question is:

"Is it allowed to use the combination of the two lamps to meet the photometric requirements."

Because the distance between the two adjacent light sources in the array does not exceed 560 mm (the sketch indicates that it is less than 550 mm), paragraph 5.1.5.2 of SAE J588 NOV84 requires that the combination of the lamps be used to meet the photometric requirements for the corresponding number of lighted sections, two in this case. Sincerely,

John Womack Acting Chief Counsel

NCC-20:ZTVinson:mar:5/19/93:OCC 8589:62992 cc: NCC-0l Subj/Chron Interps. Std. 108; redbook (3) w/sketch 8589; ztv; U:\ncc20\interp\108\8589.ztv

ID: 8589r

Open

Dr. Thomas Lckemeyer
Dept VER/LB
SWF Auto-Electric GmbH

FAX 07142/73 28 95

Dear Dr. Lckemeyer:

As you have requested, we are responding by FAX to your FAX letter of June 25, 1993, to Taylor Vinson of this Office.

Our FAX letter to you of May 28, 1993, provided an interpretation of SAE J588 NOV84, incorporated by reference in Federal Motor Vehicle Safety Standard No. 108. You mention the l990 SAE Ground Vehicle Lighting Manual which refers to SAE J588 September l970, and ask which is the correct SAE reference.

Standard No. 108 was amended with an effective date of December 1, 1990, to substitute "SAE J588 NOV84" for "SAE J588 September 1970" as the U.S. Federal requirement for turn signal lamps used as original equipment on passenger cars and other motor vehicles with an overall width of less than 80 inches overall width. Turn signal lamps may still be manufactured to the requirements of "SAE J588 September 1970" if they are intended to replace original equipment turn signal lamps that were manufactured in accordance with "SAE J588 September 1970." We understand that your earlier letter asked for an interpretation of Standard No. 108 as it related to the design of lamps for future production, and trust that this answers your question.

As you have requested, we are also FAXing a copy of Table III. Sincerely,

John Womack Acting Chief Counsel ref:108 d:7/8/93

1993

ID: 8599

Open

Mr. Frank Millar
1841 Shady Brook Drive
Thousand Oaks, CA 91362

Dear Mr. Millar:

This responds to your letter concerning Federal Motor Vehicle Safety Standard No. 105, Hydraulic Brake Systems, and Society of Automotive Engineers (SAE) Recommended Practice J201. I apologize for the delay in our response. You asked about the significance of the two documents for manufacturers and consumers. You also asked whether you are correct in interpreting section S5.2.1 of Standard No. 105 as requiring the parking brake of a Toyota Camry with a standard (stick shift) transmission to hold the car stationary on a hill with a 30 percent grade in both forward and reverse directions for five minutes. Your questions are addressed below.

By way of background, the National Traffic and Motor Vehicle Safety Act authorizes the National Highway Traffic Safety Administration (NHTSA) to issue safety standards for new motor vehicles and items of motor vehicle equipment. All motor vehicles and items of motor vehicle equipment manufactured or imported for sale in the United States must comply with all applicable safety standards.

Standard No. 105 is one of the safety standards issued by NHTSA. The standard specifies requirements for hydraulic service brake systems and associated parking brake systems, for the purpose of ensuring safe braking performance under both normal and emergency situations. The standard applies to passenger cars, multipurpose passenger vehicles, trucks, and buses with hydraulic service brake systems. Manufacturers must ensure that each new vehicle complies with each applicable requirement of the standard. The standard specifies the specific test conditions under which each performance requirement must be met.

You asked the agency to confirm your understanding that section S5.2.1 of Standard No. 105 requires the parking brake of a Toyota Camry with a standard transmission to hold the car stationary on a 30 percent grade for five minutes in both forward and reverse directions. Section S5.2.1 reads as follows:

Except as provided in S5.2.2, the parking brake system on a passenger car . . . shall be capable of holding the vehicle stationary (to the limit of traction on the braked wheels) for 5 minutes in both a forward and reverse direction on a 30 percent grade.

Section S5.2.1 thus applies to all passenger cars, except as provided in S5.2.2. The alternative requirement set forth in S5.2.2 is only available for certain vehicles with a transmission or transmission control which incorporates a parking mechanism. Vehicles with standard transmissions do not typically have such a parking mechanism. Assuming that a Toyota Camry does not have a parking mechanism, it would be required to meet the requirements of S5.2.1.

I note that, even assuming that a vehicle meets the requirements of S5.2.1, it would not follow that the parking brake system would hold the vehicle stationary on a 30 percent grade under all real world driving conditions. As indicated above, Standard No. 105 specifies specific test conditions under which its performance requirements must be met. In the case of the standard's parking brake requirements, the specified test conditions include such things as control force and test surface. Also, the requirement only applies to the limit of traction on the braked wheels. Thus, if a 30 percent grade has a slippery surface, the vehicle might slide down the grade even though its parking brake system held the wheels locked. Finally, the requirement applies only to new vehicles and not used ones.

You also asked the significance of SAE J201 to manufacturers and consumers. The Society of Automotive Engineers is an independent, non-governmental group. In some cases, NHTSA has incorporated portions of that organization's recommended practices into its safety standards. Since the agency has not done so with SAE J201, that recommended practice does not have any significance to the Federal motor vehicle safety standards. NHTSA can only comment on the significance of its own standards and regulations and not on ones issued by other organizations or agencies. Therefore, we suggest that you contact SAE concerning the significance of SAE J201.

I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact David Elias of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

ref:105 d:9/l/93

1970

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.