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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 12741 - 12750 of 16517
Interpretations Date

ID: nht92-8.6

Open

DATE: April 3, 1992

FROM: Herr Spingler -- Entwicklung Lichttechnik Systeme, Robert Bosch GmbH

TO: Richard van Iderstine -- Office of Rulemaking, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 5/29/92 from Paul J. Rice to Herr Spingler (A39; Std. 108)

TEXT:

For a new Porsche-car, we have decided to develop a headlamp as shown in the attached drawing. The lowbeam will be provided by an ellipsoid, the highbeam by a parabola. When highbeam is on, both bulbs will be on simultaneonsly.

My question is:

Will this headlamp meet the FMVSS-108-requirements concerning the location on a car?

Thanks in advance for a quick answer.

ID: nht92-8.7

Open

DATE: April 2, 1992

FROM: Michael F. Hecker -- Micho Industries

TO: Paul Jackson Rice -- Chief Counsel, NHTSA

COPYEE: M. Dunn; R. Rogers

TITLE: Re: R-BAR Passenger Restraint System

ATTACHMT: Attached to letter dated 5/14/92 from Paul J. Rice to Michael F. Hecker (A39; Std. 222); Also attached to letter dated 3/10/89 from Erika Z. Jones to Joseph Mikoll (Std. 222); Also attached to letter dated 1/8/90 from Jerry Ralph Curry (signed by Jeffrey R. Miller) to Robert J. Lagomarsino (Std. 222); Also attached to letter dated 1/31/91 from Paul J. Rice to Scott K. Hiler (Std. 222); Also attached to letter dated 11/3/88 from Erika Z. Jones (signed by Stephen P. Wood) to Joseph Mikoll (Std. 222)

TEXT:

As you are aware Micho Industries is the licensed manufacturer of the R-BAR passenger restraint which was developed to further the safety of children who ride in school buses. This system was designed by Safety Research and Manufacturing (SRM) of Jessup, PA.. For the last three years we have worked with SRM in the continuing development of the product in order to assure that it does not violate any applicable federal and state motor vehicle safety requirements. In addition it is our joint goal that the R-BAR establish a new standard for passenger protection in school bus transportation.

I am writing you in regards to a particular specification in 49 CFR, 571.222. As stated, the "purpose" of the standard is to reduce the number of deaths and the severity of injuries that result from the impact of school bus occupants against structures within the vehicle. We are, however, concerned with possible interpretations of the 4" seat performance rule as stated in 49 CFR, 571.222, section S5.1.2(c). With this in mind, we feel that:

A. The standard is not applicable to the R-BAR passenger restraint.

B. The R-BAR complies with the intent of 571.222.

In support for this position we offer the following reasons:

1. The R-BAR is not a fixed position device, nor is it a rigid component of the seat structure.

2. In the event of a rear impact, the R-BAR incorporates a design that allows it to move upward, and away, from the adjoining seat which would thus allow the minimum clearance as intended.

(This was proven in tests conducted in May 1991 at Calspan on their HYGE sled -- see attached Report No. 7925-1).

3. The standard in question (571.222, section S5.1.2(c) was written without the authors having the benefit of knowledge of this type of device and thus allowances were not included for its possible use.

We recognize that any final interpretation will be in the hands of your department and respectfully request your advice on this matter. We would ask that you advise us, prior to issuing a final interpretation, of any additional

concerns you may have so that we can supply the necessary information to address those concerns. In order to further aid you, we have available a test data book that summarizes the testing that the R-Bar has been subjected to, over the last seven years, and would gladly send it to you if you so desire. In addition video clips of the various tests can be assembled for you review.

Thank you in advance for your consideration in this matter.

Attachment

Calspan Advanced Technology Center SRM SLED TEST report no. 7925-1, May 20, 1991 prepared by David J. Travale, prepared for SRM, Inc. (Text and graphics omitted.)

ID: nht92-8.8

Open

DATE: April 1, 1992

FROM: Charles Chun -- General Manager, Kia Motors

TO: Paul Jackson Rice -- Chief Counsel, NHTSA

TITLE: Re: S5. Dynamic Performance Requirements in FMVSS 214 - Side Impact Protection

ATTACHMT: Attached to letter dated 5/22/92 from Paul J. Rice to Charles Chun (A39; Std. 214)

TEXT:

We would like to make clear the Manufactured Date in the captioned regulation.

A) What does Manufactured Date exactly mean?

Does it mean whether production date at Kia factory in Korea or the date of U.S Customs clearance ?

B) Does it mean that Manufactured Date has the same meaning with the same Model Year?

Appreciated your authoritative interpretation. Thank you.

ID: nht92-8.9

Open

DATE: March 31, 1992

FROM: Tom Mario -- Vice President Sales, Sealco Air Controls, Inc.

TO: Steve Wood -- Office Staff Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 5/21/92 from Paul J. Rice to Tom Mario (A39; Std. 121)

TEXT:

I had recent phone conversation with Mr. Richard Carter about trailer manufacturers using the standard 121 air brake system, "protected separate reservoir", after October 8, 1992.

Mr. Carter said his interpretation is that you could use, "protected separate reservoir" or 49 CFR part 571 (Docket No. 90-3; Notice 2).

Also requesting your interpretation, for full trailer, rear axles with new system (Docket No. 90-3; Notice 2) which air brake system is required for front axle (turntable) with service brake chambers?

Also multiple axle trailers, with new system (Docket No. 90-3; Notice 2) on some axles and other axles with service chambers, which air brake system is required?

ID: nht92-9.1

Open

DATE: February 18, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: William F. Russo, Esq. -- Margolis, Sakayan & Holtz

TITLE: None

ATTACHMT: Attached to letter dated 1/21/92 from William F. Russo to Steven P. Wood (OCC 6901)

TEXT:

This responds to your letter seeking an interpretation of Standard No. 210, Seat Belt Assembly Anchorages (49 CFR S571.210). Specifically, you were interested in the requirement in S4.1 that "seat belt anchorages" for particular types of seat belts shall be installed at particular seating positions. You asked for an explanation of precisely what this requirement obliges a vehicle manufacturer to do.

The term "seat belt anchorage" is defined in S3 of Standard No. 210 as "the provision for transferring seat belt assembly loads to the vehicle structure." When S4.1 of Standard No. 210 requires a "seat belt anchorage" for a seat belt to be installed at a given seating position, the manufacturer must provide a point or points for that seating position that comply with the strength requirements of S4.2 applicable to that type of anchorage and with the location requirements of S4.3 applicable to that type of anchorage. The designated point may simply be a point on the vehicle structure (floor, sides, or room, or a point on the seat itself, for instance.

The point designated by the vehicle manufacturer in response to the requirement in S4.1 need not be a prepunched or prethreaded hole, it need not be visible, and it need not include the anchorage hardware. If the agency were seeking to impose these additional conditions on anchorages, it would have included specific language to that effect in the standard. See, for example, the proposal to amend Standard No. 210 at 45 FR 81625; December 11, 1980. When these additional conditions are not expressly set forth in the text of the standard, they are not required to be included as part of the anchorage at that seating position.

I hope this information is helpful. If you have any further questions or need some additional information on this subject, feel free to contact Steve Kratzke of my staff at this address or by telephone at (202) 366-2992.

ID: nht92-9.10

Open

DATE: February 11, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: H. Ino -- Manager, Quality Assurance, Diamond Star Motors

TITLE: None

ATTACHMT: Attached to letter dated 11/26/91 from H. Ino to Paul Jackson Rice (OCC 6723)

TEXT:

I am writing in response to your letter requesting confirmation that Federal Motor Vehicle Safety Standard No. 115 Vehicle Identification Number - Basic Requirements (49 CFR S571.115) applies only to vehicles manufactured for sale in the United States. This letter confirms that Standard No. 115 and all the rest of our safety standards apply only to vehicles manufactured for sale in the United States.

Please note that in general section 108 (a)(1)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397 (a)(1)(A); the Safety Act) prohibits any person from manufacturing, offering for sale, or importing into the United States any motor vehicle manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect, unless the vehicle conforms with the standard. One such standard that is presently in effect is Standard No. 115. However, section 108(b) (3) of the Safety Act (15 U.S.C. 1397(b)(3)) provides that this prohibition of the manufacture and sale of vehicles in the United States that do not conform with all applicable safety standards does not apply to a vehicle that:

1) is intended solely for export; 2) is labeled or tagged to show that it is solely for export; and 3) is actually exported out of the United States.

Any vehicle that meets all three of these conditions need not comply with Standard No. 115 or any other of our safety standards.

I hope this information is helpful to you. If you have any further questions or need additional information, please feel free to contact Dorothy Nakama of my staff at (202) 366-2992.

ID: nht92-9.11

Open

DATE: February 11, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Woodruff Carroll -- Carroll, Carroll, Davidson, & Young

TITLE: None

ATTACHMT: Attached to letter dated 11/16/91 from Woodruff Carroll to Kathleen DeMeter

TEXT:

This responds to your letter inquiring about how NHTSA's regulations relate to snowplows. Ms. Kathleen DeMeter, the Assistant Chief Counsel for General Law, has already responded to your Freedom of Information request in a letter dated January 6, 1992. I am pleased to have this opportunity to further explain our regulations to you.

By way of background information, the National Traffic and Motor Vehicle Safety Act (the Safety Act; 15 U.S.C. 1392) authorizes this agency to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and new items of motor vehicle equipment. A snow plow that is designed and intended to be attached to a motor vehicle would be considered an item of motor vehicle equipment, within the meaning of the Safety Act. However, NHTSA has not issued any specific standards setting forth performance requirements for snow plows.

While there are no safety standards directly applicable to snow plows, the following circumstances are relevant to equipping motor vehicles with snow plows. If before the first consumer purchase, the original equipment manufacturer or an alterer equips a motor vehicle with a snow plow, the manufacturer or alterer must certify that the vehicle complies with the applicable safety standards when equipped with the snow plow.

This leads to the question of what conditions would be used to determine if the vehicle complies with the applicable safety standards when equipped with a snow plow. This question is answered in the definition of "unloaded vehicle weight" set forth in 49 CFR S571.3. "Unloaded vehicle weight," which is used to determine a vehicle's gross vehicle weight rating for the purposes of the tire and braking standards and to specify the test conditions for NHTSA's crash testing standards, is defined as "the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use."

Thus, those parts of the snow plow which are permanently attached to the vehicle and any snow plow parts that are not ordinarily removed from the vehicle would be in place and their weight would be considered in determining compliance with applicable standards. However, the snow plow blade and any other parts of the snow plow that are ordinarily removed when the snow plow is not in use would not be attached to the vehicle and the weight of these parts would not be considered in determining compliance with the applicable safety standards.

Another relevant provision of Federal law with respect to equipping a vehicle

with a snow plow is S108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)), which specifies that, "no manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard." If a manufacturer, distributor, dealer, or motor vehicle repair business added a snow plow to a motor vehicle in such away that any of the elements of design installed on the vehicle in compliance with a safety standard were "rendered inoperative," that entity would have violated the Safety Act.

This agency also has authority to investigate allegations that motor vehicles and items of motor vehicle equipment contain defects related to motor vehicle safety, and to order the manufacturer to notify owners and to remedy without charge any vehicles or items of equipment determined to contain a defect related to motor vehicle safety, as provided in sections 151-160 of the Safety Act (15 U.S.C. S1411-1420.) If there were indications that any snow plows contained a defect related to motor vehicle safety, the agency would investigate and take appropriate action. Of course, as with any investigation of alleged safety-related defects, the outcome would depend on the facts of the specific investigation.

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

ID: nht92-9.12

Open

DATE: February 11, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Thomas J. Magnan -- Sergeant, Traffic Safety Division, Metropolitan Police Department, City of St. Louis, Mo.

TITLE: None

ATTACHMT: Attached to letter dated 1/7/92 from Thomas J. Magnan to Taylor Vinson (OCC 6885)

TEXT:

This responds to your letter of January 7, 1992, to Taylor Vinson of this Office, with respect to the Hella Position Indicator Lamp. You have asked whether this item may be used on vehicles in the United States.

The National Highway Traffic Safety Administration has no authority to grant formal approval of any lighting device. The agency does, however, advise whether use of a device is legal under applicable Federal laws. The National Traffic and Motor Vehicle Safety Act provides the agency with authority to issue motor vehicle safety standards for new motor vehicles and new items of motor vehicle equipment. This agency has exercised this authority to establish Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Under Standard No. 108, trucks, buses,and multipurpose passenger vehicles whose overall width is 80 inches or more are required to be equipped with clearance lamps to indicate the overall width of the vehicle. The Hella Position Indicator Lamp could be intended for use as an original equipment clearance lamp or as a supplemental lamp on new vehicles. Although the Hella lamp is mounted on the side of the vehicle and thus indicates more than the overall width of the vehicle,it would nevertheless be acceptable as a clearance lamp if it complied with the other requirements of Standard No. 108 for clearance lamps. As a supplemental lamp, it is subject only to the restriction that it not impair the effectiveness of the original lighting equipment required by the standard. As it appears intended as a supplement to the clearance lamp, we do not judge it likely that the lamp would impair the effectiveness of the clearance lamp, or of any other rear lighting device.

It would appear, however, that the primary application of this device will be in the aftermarket. In this circumstance, Standard No. 108 would not directly apply to the Hella lamp. However, there is a provision of the Safety Act that applies to the installation of aftermarket items of motor vehicle equipment, including lamps. The Safety Act prohibits any manufacturer, distributor, dealer, or repair shop from knowingly "rendering inoperative," in whole or in part, any device or element of design installed on or in a vehicle in compliance with an applicable safety standard. The effect of this provision is to make it unlawful for any of the named commercial establishments to add or replace any lamp, reflective device, or associated equipment on a motor vehicle if the commercial establishment knows or should know that the addition of the aftermarket lighting equipment results in the vehicle no longer complying with Standard No. 108. The installation of the Hella lamp by the named commercial establishments would not appear to be a "render inoperative" violation, since, as explained above, the Hlla lamp would not appear to impair the effectiveness of any required rear fighting device.

Therefore, the manufacture and sale of this lamp would not appear to violate any of the Federal states and regulations administered by the National Highway Traffic Safety Administration. However, this does not preclude regulation of the installation and use of aftermarket devices by the individual States. For example, whether this particular lamp design could be used in Missouri would be a question to be answered under the laws of your State. We are unable to advise you on the laws of the individual States. If the Hella distributor is interested in pursuing the question of acceptability under the laws of the individual states, we suggest that he write the American Association of Motor Vehicle Administrators for an opinion. Its address is 4600 Wilson Boulevard, Arlington, Va. 22203.

ID: nht92-9.13

Open

DATE: February 11, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Anonymous

TITLE: None

ATTACHMT: Attached to letter dated 11/14/91 from anonymous to Paul Jackson Rice

TEXT:

This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard No. 114, Theft Protection. You asked whether vehicles that incorporate any of five proposed designs that your company has developed would comply with the standard's new provisions at S4.2.2(b) that permit transmission shift override devices. As you may know, that section of Standard No. 114 was amended by NHTSA after you prepared your letter. See 57 FR 2039, January 17, 1992 (copy enclosed). This letter reflects that amendment. The issues raised by your letter are discussed below.

Before discussing the substantive issues that you raised, I note that you requested confidential treatment of the identity of the source of the material that you submitted. This request was granted by NHTSA in a letter dated December 9, 1991. Accordingly, references to your identity will be deleted from the copies of your incoming letter and our response that are placed in the public docket.

By way of background information, 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 and equipment comply with applicable requirements. The following represents our opinion based on the facts provided in your letter.

Your five proposed designs can be described as follows:

PROPOSAL ONE: An override button would be provided that is covered by a small non-transparent plastic access panel on the horizontal surface of the automatic transmission shift gate. The cover would be held in place by barbed features that are incorporated into the cover and which engage with the walls of the shift gate. In order to remove the cover, one would apply a blade-like device such as a knife or screwdriver to a 2 mm vertical gap between the shift gate and the surface of the horizontal member of the cover, and pry the cover upward. A vertical load of approximately 5 to 10 kg is necessary to remove the cover. Once the cover is removed, the transmission shift lock could be defeated by depressing the override button.

PROPOSAL TWO: This design would be identical to Proposal One, except that the override button is replaced by a threaded screw. Once the cover is removed, the transmission shift lock could be defeated by using a screwdriver to turn the screw.

PROPOSAL THREE: An override device would be provided that is covered by a small non-transparent plastic access panel. The cover would be held in place by a cross recessed counter screw. In order to remove the cover, one would

use a screwdriver to remove the screw. Once the cover is removed, the transmission shift lock could be defeated by inserting a screwdriver or similar tool through the hole created by the removal of the cover screw.

PROPOSAL FOUR: An override device would be provided that is underneath the console finisher panel. A special access panel would not be provided for the override device; instead, the entire finisher panel would be removed to obtain access. The finisher panel would be fabricated from injection molded plastic resin, which has some degree of flexibility. To remove the finisher panel, one would place a screwdriver or similar tool in a 6 mm crease at the surface of the panel to housing interface and apply a prying action. Once the finisher panel is removed, the transmission shift lock could be defeated by depressing the actuation link.

PROPOSAL FIVE: An override button would be provided that is covered by a non-removable cover. The cover would have a slot to permit access to the override device. To actuate the device, a key, screwdriver, or similar tool would be inserted though the slot so that the override button is depressed.

Section S4.2.2(b) of Standard No. 114 reads as follows:

S4.2.2(b)(1) Notwithstanding S4.2.1, each vehicle specified therein may have a device which, when activated, permits moving the transmission shift lever from "park" after the removal of the key provided that steering is prevented when the key is removed.

(2) For vehicles manufactured on or after September 1, 1993, the means for activating the device shall either be operable by the key, as defined in S3, or by another means which is covered by a non-transparent surface which, when installed, prevents sight of and activation of the device and which is removable only by use of a screwdriver or other similar tool.

Section S4.2.2 (b)(1) becomes effective on September 1, 1992; section S4.2.2 (b)(2) becomes effective on September 1, 1993. Thus, vehicles manufactured between September 1, 1991 and August 30, 1992 may have a transmission shift override device provided that steering is prevented when the key is removed. Therefore, provided that steering is prevented, all five of your proposed override devices would be permitted during that time period.

For vehicles manufactured on or after September 1, 1993, an additional requirement must be met. For these vehicles, the override device must either be operable by the key defined in S3 or be operable by another means which is covered by a non-transparent surface which, when installed, prevents sight of and activation of the device and which is removable only by use of a screwdriver or other similar tool.

It is our opinion that none of your proposed designs would be operable by the key defined in S3. While the override device described in Proposal 5 could be activated by inserting a screwdriver or any key (including the key defined in S3) through the slot in the access panel, we interpret the term "operable by the key defined in S3" to refer to the normal use of the key and not to using it in place of a screwdriver.

There remains the question for each of your proposed designs of whether the override device would be operable by another means which is covered by a non-transparent surface which, when installed, prevents sight of and activation of the device and which is removable only by use of a screwdriver or other similar tool. As discussed below, it is our opinion that your Proposal 3 design would meet this requirement, your Proposal 5 design would not meet the requirement, and we are uncertain, based on the facts provided in your letter, as to whether your Proposal 1, 2, and 4 designs would meet the requirement.

We believe it is clear that your Proposals 1 through 4 designs would meet the first part of the requirement set forth above, i.e., the override device would be operable by a means which is covered by a non-transparent surface which, when installed, prevents sight of and activation of the device. The second part of the requirement is that the non-transparent surface must be removable "ONLY by use of a screwdriver or other similar tool." (Emphasis added.) It is our opinion that your Proposal 3 design would meet this part of the requirement, since the cover would be held in place by a screw and could be removed only if a person used a screwdriver or similar tool to remove the screw.

While the covers in your Proposal 1, 2 and 4 designs can be removed by using a screwdriver or similar tool to "pry" them off, it is unclear whether the covers are removable "only" by those means. In particular, we are unable to determine whether a person might pry the covers off by using his or her hands or fingernails. Therefore, we are unable to provide an opinion of whether those designs would comply with section S5.2.2(b)(2).

It is our opinion that your Proposal 5 design would not comply with section S5.2.2(b)(2), since the non-transparent surface (cover) would not prevent activation of the override device. Your letter also proposes to identify the transmission shift override device by placing the words "shift lock" in white lettering on the surface that covers the shift lock override mechanism. Nothing in Standard No. 114 or any other standard would prohibit identifying the override device in that manner. However, it might be more helpful to place the words "shift lock override" on the surface as these words more accurately describe the device that is accessible by removing the surface.

I hope this information is helpful to you. If you have any further questions or need any additional information about this topic, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992.

ID: nht92-9.14

Open

DATE: February 11, 1992

FROM: Lance Watt -- Director of Engineering, The Flxible Corporation

TO: Paul Jackson Rice -- Office of Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 4/10/92 from Paul J. Rice to Lance Watt (A39; Std. 108)

TEXT:

The Flxible Corporation is a major domestic manufacturer of city transit buses and requests an interpretation concerning FMVSS 108, "Lamps Reflective Devices, and Associated Equipment," while also referencing FMVSS 121 "Air Brake Systems."

An air brake system is used on our vehicles. As the driver starts to apply the service brake pedal to slow or stop the vehicle, a service brake stop lamp switch is activated. The stop lamp switch is installed to comply with Section S5.1.7 of FMVSS 121, "Air Brake Systems." The stop lamps are in turn activated by the stop lamp switch.

The Flxible Corporation offers optional transmissions which have internal hydraulic retarders for supplemental braking as a means to increase brake lining life. This retardation deceleration would be over and above that obtained by the normal service brake system. In our current design, the transmission retarder is electrically operated during the initial travel of the service brake pedal. As the service brake pedal is further depressed, the service brakes are activated, and this in turn triggers the stop lamp switch which in turn illuminates the stop lamps.

The Flxible Corporation has received requests from customers to activate the transmission retarder when the ACCELERATOR pedal is released. In this scenario, the service BRAKE pedal would not be used to activate the transmission retarder. However, if required, the driver could also depress the brake pedal to in turn activate the service brakes in order to achieve an even higher rate of vehicle deceleration over and above that obtained by the transmission retarder itself.

If the brake pedal were not depressed however, and with the vehicle deceleration caused solely by transmission retardation, the stop lamps would not be illuminated and therefore, following vehicles may be unaware of this sudden reduction in vehicle speed.

Some of our customers have also requested to have the transmission retarder activate the stop lamps to provide following vehicles with a warning that a sudden reduction in vehicle speed was in progress, even though it was caused by the transmission retarder as opposed to a service brake application. Again, this application of the stop lamps would be achieved by release of the accelerator and without depressing the brake pedal, and potentially without any intent to apply the service brakes on the part of the driver.

Section S5.5.4 states: "The stop lamps on each vehicle shall be activated upon application of the service brakes." This is interpreted by Flxible to mean the brake pedal would activate the service brakes which would activate the stop

lamp switch which in turn would activate the stop lights. By virtue of our customer's requests, the stop lamps would already be activated when the driver released the accelerator pedal and without any application of the brake pedal.

Flxible has in the past requested a NHTSA ruling on a further scenario outside of that, but somewhat related to that which is described here-in. Please find attached a copy of that request along with a copy of your response for reference.

Additionally, some of our customers, especially those in locations likely to experience icy or slippery road conditions, request a retarder cut off switch in order to disable the retarder and reduce the possibility of uncontrolled drive axle wheel lock-up. In cases such as this, without a dual system that would then allow stop light switch and stop light activation to be caused by application of the brake pedal as in our standard system today, a stop light activation would occur at the time of accelerator release with minimal if any change in vehicle forward speed, and again, potentially with no intent on the part of the driver to use the service brakes.

Flxible to date has resisted the customer requests as noted, however, these customers, without a specific NHTSA ruling on the request as stated above, threaten to declare Flxible a non responsive bidder on transit bus procurements. The basis of their complaints or requests in this regard stem from the fact that they require operating standardization across their various manufacturer fleets to prevent operator error or confusion.

A ruling is requested on whether a non-compliance with Section S5.5.4 of FMVSS 108 would result, if the stop lamps were activated without depressing the brake pedal as requested by our customers.

Flxible appreciates the opportunity to petition for a ruling in this complex matter so that we may use your response accordingly in responding, to our customer's requests.

Should you desire any further clarification or information on this subject, please feel free to contact the writer at (614) 362-2730.

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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