NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date |
|---|---|
| search results table | |
ID: 1985-04.37OpenTYPE: INTERPRETATION-NHTSA DATE: 11/25/85 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: P.J. Pennells TITLE: FMVSS INTERPRETATION TEXT:
November 25, 1985 P.J. Pennells Pilkington Glass Limited Triplex House Eckersall Road Kings Norton Birmingham ENGLAND B38 8SR Dear Mr. Pennells: Thank you for your letter of October 7, 1985, concerning the application of our glazing regulation to slow moving vehicles, such as agricultural vehicles and earth moving equipment. I hope the following discussion answers your questions. As with all our safety standards, Standard No. 205, Glazing Materials, applies only to vehicles classified as motor vehicles by the National Traffic and Motor Vehicle Safety Act. Section 102(3) of the Vehicle Safety Act defines the term "motor vehicle" as "any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails. The agency does not consider agricultural vehicles, such as tractors, to be motor vehicles since the legislative history of the Vehicle Safety Act indicates that Congress did not intend to cover those vehicles. Whether construction vehicles, such as earth movers, will be considered motor vehicles depends on their use. For example, construction vehicles intended and sold solely for off-road use are not. I have enclosed a copy of an information sheet prepared by the agency which discusses additional factors we consider in determining whether a vehicle meets the statutory definition of "motor vehicle." We would be glad to give you an opinion as to whether a particular construction vehicle would be classified as a motor vehicle for the purposes of our regulations, if you will provide us with specific information about the design characteristics and use of the vehicle. Since the Occupational Safety and Health Administration in the U.S. Department of Labor has regulations which effect off-road construction vehicles, I have referred a copy of your letter to that agency. I hope this information is of assistance to you. If you have any further questions, please let me know. Sincerely, Original Signed By Erika Z. Jones Chief Counsel Enclosures |
|
ID: 1985-04.38OpenTYPE: INTERPRETATION-NHTSA DATE: 11/25/85 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Mr. Ron Marion -- Specification Engineer, Thomas Built Buses, Inc. TITLE: FMVSS INTERPRETATION TEXT:
Mr. Ron Marion Specification Engineer Thomas Built Buses, Inc. P.O. Box 2450 1408 Courtesy Road High Point, N.C. 27261 This responds to your October 1, 1985 letter to this office asking whether each state has the discretion to determine whether vehicles purchased for Head Start programs should be school buses. While the memorandum you intended to enclose from Commissioner Hodges was excluded from your letter, we are able to answer your questions directly. Your first question asked, "Are Head Start Programs considered schools or school related events for preprimary students?" This agency has consistently stated that a Head Start facility is considered a preprimary school for the purpose of the National Traffic and Motor Vehicle Safety Act. Your second question asked, "Are Head Start Agencies required to provide school buses when transporting 10 or more students?: As you know, the requirements under the Vehicle Safety Act apply to the manufacture and sale of new motor vehicles, and not to motor vehicle use. The Vehicle Safety Act does not require schools to use school buses that comply with our motor vehicle safety standards for school buses. Instead, given that Head Start facilities are "schools" within the meaning of the Vehicle Safety Act, each person selling a new bus (i.e., a motor vehicle designed to carry more than 10 persons) to such a facility is required to sell a bus that complies with NHTSA's school bus safety standards. Your final question asked about state discretion to determine whether Head Start centers must provide complying school buses. The requirements governing the use of a motor vehicle after it is sold is a matter of state law. While NHTSA has issued recommendations to states regarding school bus operation in Highway Safety Program Standard No. 17, Pupil Transportation Safety (copy enclosed), this agency has no requirement that Head Start centers must use complying school buses. On the other hand, the responsibility of school bus sellers to comply with the requirements of the Vehicle Safety Act, and to sell a vehicle that complies with all applicable safety standards, including the school bus safety standards, is a Federal requirement. Accordingly, the states have no discretion to permit persons to sell new buses to Head Start centers if those buses do not comply with the motor vehicle safety standards for school buses. For your future reference, Mr. Tilton is no longer with this agency. If you have further questions, please do not hesitate to contact us. Sincerely, Original Signed By Erika Z. Jones Chief Counsel Enclosure |
|
ID: 1985-04.39OpenTYPE: INTERPRETATION-NHTSA DATE: 11/25/85 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: EPL Incorporated TITLE: FMVSS INTERPRETATION TEXT:
Mr. James L. Loden President, EPL Incorporated 200 Campus Drive, RD Pemberton Farms Research Campus Mt. Holly, NJ 08060
Dear Mr. Loden:
Thank you for your July 16, 1985 letter inquiring about the existence of any Federal safety requirements applicable to your projected sale of heated windshield wiper blades. You also asked if Federal testing or research testing or research is being conducted on windshield wiper systems.
Under the National Traffic and Motor Vehicle Safety Act, this agency has issued Federal Motor Vehicle Safety Standard No. 103, Windshield Defrosting and Defogging Systems and No. 104, Windshield Wiping and Washing Systems, which are applicable to new motor vehicles. While these standards do not regulate the heating component of wipers, they do, among other things, require that a defrosting or wiping system clear a minimum percentage of a vehicle's windshield. In addition, Standard No. 107, Reflecting Surfaces, also applies to new motor vehicles. This standard sets limits on the glare from certain metal components, including windshield wiper blades, in the driver's field of view. Its purpose is to reduce the likelihood that unacceptable glare from reflecting surfaces will hinder safe and normal operation of the vehicle. Copies of these three standards are enclosed.
If a new vehicle equipped with your blade did not comply with Standard No. 103, Standard No. 104, or Standard No. 107 due to some aspect of that blade, the sale of that car to the public would be a violation of the prohibition in section 108(a)(1)(A) of the Act against the sale of noncomplying vehicles.
As to used vehicles, you should be aware that section 108(a)(2)(A) of the Act prohibits manufacturers, distributors, dealers, and vehicle repair businesses from knowingly rendering inoperative equipment or elements of design installed on a vehicle under Federal motor vehicle safety standards. Care should be taken that the installation of your product would not have that effect. A rendering inoperative might occur if, for example, your blade were not large enough to enable the wiping system to clear a sufficient area of the windshield. We urge you therefore to ensure that the substitution of your blade for an original equipment blade provided by a vehicle manufacturer would enable the wiping or defrosting system to continue to perform as required by Standard No. 103 and No. 104, and would not produce unacceptable glare in the driver's field of view, as prohibited by Standard No. 107.
Copies of the windshield compliance test reports for Standard Nos 103 and 104 are available from the agency's Technical Reference Division. Copies of these reports can be purchased by contacting Mr. Robert A. Hornickle (202-426-2987).
I hope this information is helpful to you.
Sincerely,
Erika Z. Jones Chief Counsel Enclosures
E P L Incorporated 200 Campus Dr. RD 1 Pemberton Farms Research Campus Mt. Holly, NJ 08060
July 16, 1985
Mr. Steven Oesch Office of Chief Counsel National Highway Traffic Safety Administration 400 Seventh Street, S.W. Washington, D.C. 20590
Dear Mr. Oesch:
During a recent conversation, Edward Jetner, Staff Engineer for the Office of Vehicle Safety Standards, suggested I contact you for information on the Federal Motor Vehicle Safety Standards as they apply to a new product we intend to manufacture.
Our company, EPL Incorporated, is starting to manufacture a heated windshield wiper blade. We call it "Thermoblade", and it is designed for use on motor vehicles of all types. Thermoblade is an important safety item as it prevents snow and ice accumulation on the wiper blade and enables it to clean the windshield and provide good visibility for the driver even under the most severe weather conditions.
Is the product we intend to manufacture covered by certain Federal Motor Vehicle Safety standards? Has any Federal testing been done, or are any of our Government's testing laboratories involved in any research and development on windshield wiper systems? Any information you can give us which will help us launch our new product will be very much appreciated. Should you need more information, please call me at 609-261-6000.
Sincerely,
James L. Loden President |
|
ID: 1985-04.4OpenTYPE: INTERPRETATION-NHTSA DATE: 10/25/85 FROM: AUTHOR UNAVAILABLE; Barry Felrice; NHTSA TO: Karl-Heinz Faber -- Vice President, Product Compliance and Service, Mercedes Benz of North America, Inc. TITLE: FMVSS INTERPRETATION TEXT:
Mr. Karl-Heinz Faber Vice President, Product Compliance and Service Mercedes-Benz of North America, Inc. One Mercedes Drive Montvale, NH 07645
I am writing in response to your letters about the headlamp cleaning systems you intend to install on certain 1986 model year vehicles. Your letters provide information about these systems and their performance. My staff has carefully reviewed the information and how it relates to Standard No. 108. "Lamps, Reflective Devices and Associated Equipment."
Our finding is that headlamp cleaning systems as proposed would be governed by paragraphs S4.1.1.36(b)(3), S4.1.3. and S4.3.1.1. The intent of the requirements in these paragraphs is 1) to assure mechanical aimability of the lamp as installed in the vehicle, and 2) to assure that all photometric performance requirements are met with and without installation of auxiliary vehicle parts or accessories, (and if performance degradation must occur, to assure that an auxiliary lighting device is provided). Additionally, the "fail safe" requirements of Standard 112, "Headlamp Concealment Devices" provides a precedent for a requirement that a headlamp should meet all photometric performances requirements, should a wiper fail.
In viewing your company's systems relative to the requirements, it appears possible to design a replaceable bulb headlamp for a specific vehicle application which includes a wiper type headlamp cleaning system, that meets the intent of the law. This could occur if the headlamp system and cleaning system were designed to meet the requirements together: i.e., the photometric performance requirements of FMVSS No. 108 could be met with the wipers in any achievable position and with any standardized replaceable light source. The system would also have to provide for the wiper to accommodate mechanical aiming. The information presented by you appears to show that the design of your system has taken these needs into account. NHTSA would anticipate that any replaceable bulb headlamp system in such an application would be certified by the vehicle manufacturer to meet the performance requirements using a standardized replaceable light source which has minimum lumen output and which has the filament at the maximum out of position tolerance, any replacement headlamp, and any headlamp cleaning system parts. This would be necessary to ensure that the vehicle would remain in compliance when replacement parts are used.
In consideration of the above, NHTSA believes that replaceable bulb headlamp systems with wiper type cleaning systems designed to be compatible and designed to conform to Standard 108 are permissible under the present Standard.
In summary, NHTSA views the use of the wiper type headlamp cleaning system in conjunction with replaceable bulb headlamps as permissible so long as due care is taken to ensure that the systems are designed to conform together, and can remain in compliance in the event of parts replacement.
Sincerely, Associate Administrator for Rulemaking |
|
ID: 571.141 NCC-230601-001 Nagaraj-SuperhornOpenSeptember 13, 2023 Dear Mr. Nagaraj, This letter responds to your inquiry to the National Highway Traffic Safety Administration (NHTSA) regarding compliance of a new horn function named “Superhorn” with Federal Motor Vehicle Safety Standard (FMVSS) No. 141. Based on the information you provided, as explained in more detail below, we have concluded that Superhorn is permissible under FMVSS No. 141. Description of the Superhorn You state that Superhorn is a feature that plays a horn sound through the same system used for emitting the pedestrian alert sound; the vehicle would not be equipped with a traditional horn trumpet. In addition to being user-actuated, you state that Superhorn would resemble a traditional horn both in sound and loudness and would only be played for the duration of continuous horn control actuation (up to a maximum of a 60 seconds before the system times out). You further state that Superhorn is independent of the pedestrian alert system, and that the pedestrian alert system would be emitted alongside the Superhorn sound from the same speaker system. You acknowledge that the pedestrian alert sound may be masked to some extent by the horn when the horn is actuated. Background NHTSA established FMVSS No. 141 in 2016, pursuant to the Pedestrian Safety Enhancement Act of 2010 (PSEA).1 The standard sets minimum sound level requirements for hybrid and electric light vehicles operating at low speeds and aims to reduce injuries to pedestrians and other road users by increasing the detectability of hybrid and electric vehicles. NHTSA does not approve motor vehicles or motor vehicle equipment and does not determine whether a product conforms to the FMVSS outside of an agency compliance proceeding. Discussion There are three requirements of FMVSS No. 141 pertinent to the analysis of the Superhorn. Sound performance requirements (S5.1 through S5.4) S5.1 through S5.4 describe performance characteristics related to measured volume and frequency bands of sounds emitted from covered vehicles. The volume and frequency requirements described in S5.1 through S5.4 are vehicle-level requirements; individual sounds such as horns, including the proposed Superhorn, are not required to independently meet those requirements.2 The performance requirements described in S5.1 through S5.4 are intended to measure the detectability of a vehicle during routine operation. Since the Superhorn is not automatically engaged during routine operation, the Superhorn may not be used to meet FMVSS No. 141’s minimum required sound levels.3 Sameness requirement (S5.5) S5.5 describes the “Sameness requirement,” which requires all vehicles of the same make, model and trim equipped with a pedestrian alert sound to emit the same set of sounds. NHTSA has previously explained that the Sameness requirement, which stems from the PSEA,4 only applies to sounds added to the vehicle for the purposes of complying with the standard.5 The agency believes that this interpretation is still appropriate. Requiring all sounds produced by non- pedestrian alert systems to be identical would be overly burdensome and would prevent certain optional equipment that could affect the sound of a vehicle from being offered for sale. Even though the Superhorn would be played through the same speaker system as the pedestrian alert system, according to your description it is not being added to meet volume and frequency requirements of FMVSS No. 141, and it is only active during horn control actuation. Therefore, Superhorn is not subject to the Sameness requirement. Prohibition on altering the sound of a covered vehicle (S8(b)) S8(b) prohibits providing “any mechanism, equipment, process, or device intended to disable, alter, replace, or modify the sound emitting capability of a vehicle subject to this standard, except in connection with a repair of vehicle malfunction or to remedy a defect or non-compliance.” S8(b) is derived from a similar provision in the PSEA.6 In proposing S8(b), NHTSA described the intention of the provision as “to avoid the situation where vehicle sounds are changed, at the request of the consumer, to something individualized and no longer associated with the specific make/model of motor vehicle, or indeed even recognizable as a motor vehicle at all.”7 NHTSA reaffirmed this position in response to a petition for reconsideration, stating that S8 is intended to prevent access to vehicle features that could modify or adjust the emitted sound or render it noncompliant.8 As a practical matter, NHTSA has not applied S8(b) to other vehicle devices or mechanisms such as traditional horns or audio systems, even though these systems have the potential to alter the sound produced by vehicles and how they are perceived by pedestrians. NHTSA views S8(b) as preserving the integrity of the pedestrian alert system and, more generally, the vehicle’s detectability by pedestrians. Devices that directly touch upon the vehicle alert system, including a vehicle’s pedestrian alert speakers or audio file, receive a higher level of scrutiny. This is not to imply, however, that these are the only systems that may potentially run afoul of S8(b); devices or mechanisms that supersede or replace the pedestrian alert sound may also be found non-compliant. NHTSA believes that the Superhorn, as it is described in your correspondence, does not conflict with S8(b). From your description, the pedestrian alert would continue to play the same set of sounds unaltered and concurrent with the Superhorn for the duration of horn control actuation. As you noted, the Superhorn has the potential to mask the pedestrian alert, in much the same way as a traditional horn may mask a pedestrian alert. However, the pedestrian alert would be masked with a trumpet sound resembling the tone, pitch, and loudness of a traditional car horn and only while the Superhorn sounds. Trumpet horn sounds are distinctive and recognized as a warning to pedestrians and other road users of an imminent hazard such as a vehicle collision. NHTSA notes that this interpretation is based on the description of the Superhorn you provided. If the Superhorn’s performance varies in any way materially from the description you provided, this interpretation will no longer be applicable. For example, if the Superhorn played in the absence of continuous horn control actuation, played for a longer duration, played a sound that made vehicles less identifiable as a vehicle, or disabled the pedestrian alert sound, then the feature would likely be deemed a device that alters, disables, or replaces the pedestrian alert in contravention of S8(b) or a pedestrian alert subject to the Sameness requirement in S5.5. I hope this information is helpful. If you have any further questions, please feel free to contact Paul Connet of my staff at this address or at (202) 366-5547.
Sincerely,
John Donaldson
1 Pub. L. No. 111-373, 141 Stat. 4086 (Jan. 4, 2011). 2 Hybrid and electric vehicles are not required to have a dedicated pedestrian alert sound; vehicles that produce sufficient sound to meet the performance requirements described by S5.1-S5.4 may satisfy the requirements of FMVSS no. 141 without a dedicated alert system. See 81 FR 90416, 90450 (Dec. 14, 2016). 6 See PSEA § 3(2).
Dated: 9/13/23 Ref: Standard No. 141 |
2023 |
ID: NCC-200810-001-HMSL Hazard Lamp - RostraOpenMarch 5, 2024 Mr. Peter Kallgren Vice President, Sales & Marketing Rostra Precision Controls, Inc. 2519 Dana Drive Laurinburg, NC 28352
Dear Mr. Kallgren, This responds to your company’s request for interpretation regarding whether a replacement center high mounted stop lamp (CHMSL) intended to be installed on a truck cap is permitted to flash when a vehicle’s hazard lamps are activated. As we explain below, it is our view that it would not be permissible for the CHMSL to flash as a supplemental hazard warning lamp because our regulations require that a CHMSL be steady burning when activated. We respond to your question in more detail below. By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards (FMVSS) that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. Chapter 301). NHTSA does not provide approval of motor vehicles or motor vehicle equipment, and NHTSA does not determine compliance of a vehicle or item of motor vehicle equipment outside the context of an actual enforcement proceeding. Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture. The following represents NHTSA’s opinion regarding the applicability of FMVSS No. 108 requirements to your proposed CHMSL, based on the information you have provided. Under 49 U.S.C. 30122, a vehicle manufacturer, distributor, dealer, rental company, or repair business generally may not knowingly “make inoperative” any part of a device or element of design installed in or on a motor vehicle in compliance with an applicable FMVSS. You ask specifically about a CHMSL that would be a supplement to the existing one. This additional lamp is made necessary because, without one, a truck cap installed by your company would “make inoperative” the existing CHMSL by creating an obstruction or blockage. FMVSS No. 108 specifies requirements for original and replacement lamps, reflective devices, and associated equipment. The standard contains a number of specific requirements for certain lamps, such as headlamps, turn signal lamps, and high-mounted stop lamps, among others. In order to not “make inoperative” the required CHMSL, the lamp you propose to mount on the truck cap to avoid the obstruction would need to meet all the requirements of FMVSS No. 108 that apply to the original CHMSL. A CHMSL, by definition under paragraph S4, is expected to be steady burning, and it is also expressly required to be steady burning by paragraph S6.1.5, Activation, which states in relevant part that “Each lamp must be activated as specified … in response to the inputs specified in Table I ….” Table I-A, in turn, requires high mounted stop lamps to be “steady burning” and to “be activated only upon application of the service brakes or [ ] be activated by a device designed to retard the motion of the vehicle.” You describe a situation in which a CHMSL mounted on a truck cap is wired into a vehicle’s signal lighting system in a manner that causes the CHMSL to flash with the turn signals when the vehicle’s hazard warning system is activated. Accordingly, you ask whether it is permissible for the CHMSL to be considered a supplemental hazard lamp that flashes when the vehicle’s hazard warning system is activated. Because FMVSS No. 108 requires a CHMSL to be steady burning, as explained above, a CHMSL that flashes would not comply and would fail to prevent the cap obstruction from rendering inoperative the CHMSL required by FMVSS No. 108. The fact that hazard warning lamps have been activated does not change the requirement that the CHMSL be steady burning, and FMVSS No. 108 does not permit a CHMSL to cease to function as a CHMSL and begin to function as a supplemental hazard warning lamp simply because the hazard warning system is activated. This is consistent with past NHTSA interpretations, where the agency stated that “causing the center high-mounted stop lamp to flash would not change the center lamp into a ‘hazard warning lamp’ within the meaning of Standard No. 108.”1 If you have further questions, please contact Eli Wachtel of my staff at (202) 366-2992. Sincerely, John Donaldson Acting Chief Counsel
1 Letter to Randy I. McClanahan (April 2, 1996), available at https://www.nhtsa.gov/interpretations/11610ztv. Dated: 3/5/24 Ref: Standard No. 108 |
2024 |
ID: 571.108--NCC-230201-001 LED Headlights_ M. BakerOpenFebruary 13, 2024 Mr. Mark Baker, B.S.E.E. Soft Lights 9450 SW Gemini Drive PMB 44671 Beaverton, OR 97008 mbaker@softlights.org Dear Mr. Baker: This responds to your letter and email dated June 27, 2021 and October 31, 2021, respectively, regarding the legal status and safety of motor vehicle headlamps that use light-emitting diode (LED) technology as the light source. Please note that our answer below is based on our understanding of the specific information provided in your letter and email. You ask about the “legality of LED headlights.” You state your belief that Federal Motor Vehicle Safety Standard (FMVSS) No. 108 does not regulate “peak luminance, absolute spectral power distribution or flicker” and that the standard “only applies to spherical emitters such as tungsten- filament and gas-discharge and is not applicable to non-uniform luminance flat-source emitters such as LED chips.” You ask whether it is “NHTSA’s position that FMVSS No. 108 is only applicable to uniform luminance emitters which can be regulated by setting maximums for luminous intensity without the need of setting peak luminance maximums” and whether “NHTSA [has] approved the use of spatially heterogeneous visible radiation for use as the light source used in vehicle headlights.” You state your concerns about adverse health impacts due to the performance characteristics of LEDs, such as high peak luminance, high-color temperature, high-energy blue wavelength light, and flicker. You request NHTSA’s opinion about the “sufficiency” of FMVSS No. 108 regarding these health concerns. We understand you to use “uniform luminance emitters” to refer to filament (halogen/tungsten) and high-intensity discharge (HID) light sources, and “non-uniform” or “heterogenous emitter” to refer to LED light sources. We therefore understand you to be asking whether LEDs are legal as a light source in motor vehicle headlamps under FMVSS No. 108, and, if they are legal, what is NHTSA’s position on the safety of LED light sources in headlamps with respect to “eye safety, mental safety, and visual performance.” Background NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act, 49 U.S.C. Chapter 301) to issue FMVSS that set performance requirements for new motor vehicles and new items of motor vehicle equipment. The Safety Act requires manufacturers to self-certify that their vehicles and equipment conform to all applicable FMVSS in effect on the date of manufacture. NHTSA also investigates safety-related defects. FMVSS No. 108, “Lamps, reflective devices, and associated equipment,” applies to “[p]assenger cars, multipurpose passenger vehicles, trucks, buses, trailers (except pole trailers and trailer converter dollies), and motorcycles” and covers, among other things, “original and replacement lamps, reflective devices, and associated equipment” for motor vehicles. The standard specifies performance requirements for headlamps. The most common types of headlamps are integral beam (S10.14) and replaceable bulb (S10.15, S11) headlamps. NHTSA has stated that LED light sources are permitted as part of an integral beam headlamp if they are wired in series such that a failure of one LED would cause all the LEDs to cease functioning, and they otherwise comply with all relevant FMVSS.1 Paragraph S4 of FMVSS No. 108 defines an integral beam headlamp as “a headlamp … comprising an integral and indivisible optical assembly including lens, reflector, and light source, except that a headlamp conforming to paragraph S10.18.8 or paragraph S10.18.9 may have a lens designed to be replaceable.” The standard does not contain performance requirements for a light source that is part of an integral beam headlamp, but instead specifies performance requirements for the complete headlamp. These include (among other things) photometry, through minimum and maximum candela at specified test points,2 color, which must remain within specified boundaries,3 and that the headlamp be steady burning.4 While LED light sources that are part of an integral beam headlamp are permitted as noted above, no LED light source is currently permitted to be used in a replaceable bulb headlamp. FMVSS No. 108 contains specific requirements for the replaceable light sources (i.e., bulbs) used in replaceable bulb headlamps. These requirements are intended to support light source interchangeability. Paragraph S11 of the standard requires that “[e]ach replaceable light source must be designed to conform to the dimensions and electrical specifications furnished with respect to it pursuant to part 564 of this chapter[.]”5 Part 564 requires that replaceable bulb manufacturers submit to NHTSA for review and acceptance various design specifications for the bulb. If accepted, this design information is then placed in a publicly available docket to facilitate the manufacture and use of those light sources. As of the date of this letter, no submission that includes LEDs as the light source for a replaceable bulb headlamp has been listed in the docket. Therefore, no LED replaceable light source may be used in a replaceable bulb headlamp. Discussion Pursuant to FMVSS No. 108, paragraphs S4 and S10.14, LEDs are allowed to be used as a light source in integral beam headlamps as long as the headlamp conforms to all applicable headlamp requirements in FMVSS No. 108. However, LEDs are not currently permitted in a replaceable bulb headlamp. Nevertheless, illegal LED headlamp replaceable light sources may be available for purchase on the internet, and although these lights do not conform to the requirements of FMVSS No. 108, some consumers purchase and install these LED light sources in their replaceable bulb headlamps. While NHTSA regulates the manufacture and sale of light sources, it generally does not regulate the modifications individuals make to their own vehicles. It is therefore left to State law to address installation of an LED replaceable light source in a headlamp. FMVSS No. 108 does not directly regulate what you describe as peak luminance as measured in nits or the spectral power distribution of the headlamp light source. However, this is indirectly regulated through the headlamp performance requirements, such as the photometry and chromaticity requirements. Additionally, flicker is regulated through the requirement that lower beam headlamps be steady burning. We also note that, although FMVSS No. 108 requires that the light emitted by headlamps be white, the permissible boundary of white includes colors that may be perceived by the human eye as white with a yellow tint and white with a blue tint.6 In your communications, you raise concerns about the health impacts of LED headlamps. We are aware of concerns raised about possible adverse effects of certain LED devices, particularly as used in street lighting that emits excess blue light.7 NHTSA’s focus is on automotive safety, but the agency recognizes that separate expertise resides in sister agencies that are health-focused, such as the Food and Drug Administration. I hope this information is helpful. If you have any further questions, please feel free to contact Eli Wachtel of my staff at this address or at (202) 366-2992. Sincerely, John Donaldson
2 Photometry requirements for headlamp systems can be found in FMVSS No. 108, Tables XVIII and XIX. 3 See FMVSS No. 108, Table I-a (headlamp color). Chromaticity requirements are pursuant to FMVSS No. 108 S14.4. 4See FMVSS No. 108 Tables I-(a and c). NHTSA has stated that “steady burning” means “light that is essentially unvarying in intensity.” See Letter from Frank Berndt, Chief Counsel, NHTSA, to United Sidecar Association, Inc. (Feb. 9, 1982). A device may fail to meet this requirement where the driver “would not see a signal that was consistent or reliable in its meaning.” See Letter from Paul Jackson Rice, Chief Counsel, NHTSA, to Bob Abernathy, Idea’s Inc. (Sept. 7, 1990) (applying steady burning in a taillamps context). In the context of a modulating motorcycle headlamp, we have stated that “there is no failure to conform if the modulating light from the lamp is perceived to be a steady beam.” Letter from John Womack, Acting Chief Counsel, NHTSA, to Joe De Sousa (March 10, 1994). 5 See Letter from John Womack, Acting Chief Counsel, NHTSA, to Nancy Tavarez, Beitrix Industries (Aug. 30, 1995) (clarifying application of Part 564 to replaceable headlamp bulbs). 6 Letter from Frank Seales, Jr., Chief Counsel, NHTSA, to Richard Hodson, (July 4, 2000) (stating that “SAE J578c defines white by blue, yellow, green, red, and purple boundaries within a chromaticity diagram. Thus, it is possible to design a headlamp that emits a light that approaches the blue boundary and is perceived as having a blue tint but which nevertheless remains within the boundaries that define "white." These headlamps would comply with the color requirements of Standard No. 108.”). 7 See “AMA adopts guidance to reduce harm from high intensity street lights,” American Medical Association, June 14, 2016, available at https://www.ama-assn.org/press-center/press-releases/ama-adopts-guidance-reduce-harm-high- intensity-street-lights. |
2024 |
ID: NCC-230308-001 NelsonMullinsParkingBrakeIndicatorInterpOpenOctober 31, 2024 Ms. Christie L. Iannetta Dear Ms. Iannetta: This interpretation responds to your letter regarding Federal Motor Vehicle Safety Standard (FMVSS) No. 135, Light vehicle brake systems. Specifically, you asked about paragraph S5.5.1 of FMVSS No. 135, which outlines the requirements for when certain brake indicators must be activated. Your question focuses on subparagraph (c), which requires that an indicator be activated when there is “[a]pplication of the parking brake.” You asked the agency to confirm that “a parking brake visual indicator that illuminates when a driver intentionally activates the electronic parking brake via the park brake control meets the requirements of FMVSS No. 135, S5.5.1(c), but that when the same electronic parking brake is automatically applied by the vehicle, the parking brake visual indicator may, but is not required, to illuminate to be considered compliant with this same provision.” Based on the information you have provided, our answer is that this requested confirmation does not provide an accurate understanding of FMVSS No. 135. To comply with FMVSS No. 135, a parking brake indicator must be activated whenever a parking brake is engaged, regardless of how the parking brake is applied. Background Please also note that our answer below is based on our understanding of the specific information provided in your letter. This interpretation letter does not have the force and effect of law and is not meant to bind the public in any way. This letter is intended only to provide clarity regarding existing requirements under the law and represents the opinion of the agency on the questions addressed in your letter at the time of signature. FMVSS No. 135 Your Question and NHTSA’s Response In addition to the manual application of the parking brake, your letter indicates that there are scenarios when the EPB automatically engages, even when the driver does not manually activate the EPB, including when the vehicle is shifted into park. You explain that if a driver puts the vehicle in park and does not manually apply the parking brake, the vehicle will automatically apply the EPB. If the vehicle automatically applies the EPB, the parking brake indicator is not activated. Lastly, you indicate that when the driver shifts out of park, the EPB system is automatically deactivated. In your letter, you assert the manufacturer’s view that this system is compliant with FMVSS No. 135 S5.5.1(c) because the regulation requires display of the parking brake only when the driver manually applies the parking brake. You point to previous interpretations that NHTSA has published, where we explain that the parking brake indicator requirement was promulgated to ensure drivers do not drive with the parking brake engaged. You assert that because the manufacturer’s EPB system eliminates this risk, the system should be considered compliant. Additionally, you assert that the regulatory history and language of the standard point to this system being compliant under paragraph S5.5.1. After careful consideration of both the standard and the arguments made in your letter, the agency has concluded that the EPB system described in your letter would be considered noncompliant with FMVSS No. 135 S5.5.1(c). As discussed above, FMVSS No. 135 S5.5.1(c) requires that if a vehicle ignition is switched to the “on” position and the parking brake is applied, an indicator must activate to inform the driver of the status of the parking brake. From the details in your letter, there would be scenarios where the vehicle you described would have the ignition switched to the “on” position with the parking brake applied, but the parking brake indicator would not be activated. To use the example from your letter, if a driver puts the vehicle in the park position and does not activate the parking brake manually, the parking brake will automatically apply, but no parking brake indicator will be active. The system you describe in Your letter asserts that the phrase “application of the parking brake” in paragraph S5.5.1(c) refers to an action that the driver takes via the “parking brake control.” You state that a driver cannot “apply” a parking brake system, but only the control, meaning that the parking brake indicator requirement only applies when the driver manually applies the parking brake. We disagree with this reading, which is inconsistent with both the language and the intent of the standard. Had S5.5.1(c) been intended to cover only manual application of the parking brake control, it would say so. Other parts of FMVSS No. 135 refer to application and activation of the “parking brake control”1; by contrast, S5.5.1(c) refers more generally to the “parking brake.” Moreover, FMVSS No. 135 makes multiple references to manual application, actions, or controls, without doing so in S5.5.1(c).2 As you state in your letter, when FMVSS No. 135 was first promulgated, manual application of the parking brake was the only way a parking brake could be engaged. However, FMVSS No. 135 has been updated multiple times since it was first issued in 1995, including as recently as 2022,3 and it has never been amended to specify that S5.5.1(c) applies only to manual application of the “parking brake control.” This history, and the lack of a manual application requirement or reference to the parking brake control in S5.5.1(c), show the agency intended the parking brake indicator to be active whenever the parking brake is engaged, regardless of how the brake is engaged. Moreover, if S5.5.1(c) covered only manual application of the parking brake control, then no indicator would be required when a vehicle automatically engages the parking brake, even if nothing prevents the vehicle from driving during this engagement—a circumstance when an indicator would be especially essential because the driver may not have consciously activated the parking brake. In fact, your letter’s description of the manufacturer’s EPB system suggests there may be circumstances where the parking brake in the manufacturer’s vehicle is automatically engaged other than when the driver shifts the vehicle to “Park.” The distinction your letter makes between a vehicle’s “parking brake” and its “parking brake system” does not change this analysis. “Parking brake system” has no regulatory definition.4 “Parking brake,” which is the term used in S5.5.1(c), is defined as “a mechanism designed to prevent the movement of a stationary motor vehicle.”5 The definition does not distinguish between mechanisms that are activated by a designated manual control and mechanisms that are activated by other means. S5.5.1(c) simply requires activation of the indicator when the parking brake mechanism is engaged. The agency has also considered the arguments you made in your letter regarding previous interpretations NHTSA has published on the parking brake indicator requirement. NHTSA has indicated in interpretations that the purpose of the parking brake indicator requirement is to prevent drivers from driving their vehicles with the parking brake activated. Doing so could potentially lead to excessive wear on the transmission and parking brake system, which could cause a variety of safety issues.6 However, just because a manufacturer has designed a system that purports to resolve, though other means, a safety concern addressed in an FMVSS does not mean that it is not bound by the requirements of the FMVSS or that it may introduce noncompliant motor vehicles or motor vehicle equipment to the market. If a manufacturer believes that it has developed technology that makes certain regulatory requirements unnecessary, it may petition the agency for a rulemaking to amend the relevant requirements. It may also request an exemption from an applicable standard if it has reason to believe it is eligible.7 Otherwise, the current requirements apply. Accordingly, the plain meaning and intent of S5.5.1(c) is for the parking brake indicator to be active any time the parking brake is engaged and the vehicle’s ignition is in the “on” position. This requirement applies regardless of whether the parking brake is engaged through the manual application of the designated parking brake control or through other means. I hope this letter answers all of your questions. If you have any further questions regarding this matter, please feel free to contact Mr. Matthew Filpi of my staff at (202) 366-2992.
Dated: 10/31/24
1 See FMVSS 135 S.7.12.2(b), (i), (l). |
2024 |
ID: NCC-230120-001 571.108 Peterson Trailer Auxiliary Door Light 11.06.24 signedOpenNovember 6, 2024 Mr. Donald Lane Peterson Manufacturing Co. 4200 E. 135th Street Grandview, MO 64030
This responds to your letter, received January 6, 2023, in which you requested a letter of interpretation asking whether a lamp located on the front of a trailer that would illuminate green or red to indicate whether the trailer doors are open or closed is compliant with Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, reflective devices, and associated equipment. Based on the information you provided in your letter, as explained in more detail below, we have concluded that installing the lights as described would not be permissible under FMVSS No. 108. In responding to this request, NHTSA notes that the contents of this letter do not have the force and effect of law and are not meant to bind the public in any way. This letter is only intended to provide clarity regarding existing requirements under the law at the time of signature. Background NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act, 49 U.S.C. Chapter 301) to issue FMVSS that set performance requirements for new motor vehicles and new items of motor vehicle equipment. The Safety Act requires manufacturers to self-certify that their vehicles and equipment conform to all applicable FMVSS in effect on the date of manufacture. NHTSA also investigates safety-related defects. After first purchase of a vehicle or equipment in good faith other than for resale, section 30122 of the Safety Act requires that a manufacturer, distributor, dealer, rental company, or motor vehicle repair business not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable motor vehicle safety standard. This letter represents NHTSA’s opinion concerning whether your design, as you describe it, would be permitted under FMVSS No. 108 and section 30122. In your letter, you state that you have been asked to install an “auxiliary light” on trailers at or over 2032mm in width and 8.1m in length. The light would be installed on the front of the trailer “so as to be visible to the driver in the driver’s side mirror” and would illuminate green when the trailer doors are shut and red when at least one of the trailer doors are open. Although it is not clear from your description, we assume that the light would also be visible to other individuals looking at the trailer from the front. You also state that you intend for the lamp to only illuminate on the private property of the trailer owner, not on other roads. You ask whether the light could be made with green and red LEDs and clear lenses or in the alternative use green or red lenses. Requirements of the Standard FMVSS No. 108 specifies requirements for original and replacement lamps, reflective devices, and associated equipment, including for trailers. For auxiliary lamps, the primary restriction imposed by FMVSS No. 108 is by S6.2.1, which states that “[n]o additional lamp, reflective device, or other motor vehicle equipment is permitted to be installed that impairs the effectiveness of lighting equipment required by this standard.” Both original equipment and aftermarket lighting can run afoul of the “make inoperative” provision, and NHTSA considers the installation of an aftermarket lamp to violate the “make inoperative” provision if the installation of the same lamp as original equipment would violate FMVSS No. 108.1 Therefore, while you do not state in your letter whether your installation would be as original equipment or in the aftermarket, we conduct the same impairment analysis. These prohibitions bar installation by a manufacturer, distributor, dealer, rental company, or motor vehicle repair business of lamps that would impair the effectiveness of required lighting, but do not apply to the owner of a vehicle. Typically, the impairment determination under FMVSS No. 108 S6.2.1 is made on a case-by- case basis and considers four main characteristics of the auxiliary lamp to analyze whether it impairs the effectiveness of required lighting: the brightness, color, location, and activation pattern of the lamp. This list is not exhaustive and other considerations may be relevant to the analysis. NHTSA has long maintained that highway traffic safety is enhanced by drivers’ familiarity with established lighting schemes, which facilitates their ability to instantly recognize the meaning the lamps convey and respond accordingly. Therefore, NHTSA has interpreted the impairment provision to prohibit auxiliary lamps that are colors and are mounted in locations which are likely to cause confusion to other road users. For auxiliary lamps located on the front of vehicles, these colors include red, which could be confused for a taillamp or stop lamp, and green, which typically conveys the message that one may proceed forward and could therefore impair required lighting that indicates caution.2 1 See, e.g., Letter to Timothy C. Murphy (Nov. 1, 2004), available at For required lighting relevant to your inquiry, FMVSS No. 108 requires that all trailers have two red taillamps and two red stop lamps on the rear of the trailer, at the same height, symmetrically about the vertical centerline, and as far apart as practicable. Also, all trailers of 2032 mm or more in width must have three red identification lamps on the rear, at the same height as one another, as close to the top of the trailer as practicable and as close as practicable to the vertical centerline of the trailer, with lamp centers spaced not less than 6 inches or more than 12 inches apart. Additionally, such trailers must also have two amber clearance lamps on the front and two red clearance lamps on the rear, symmetrically mounted about the vertical centerline as near the top as practicable to indicate the overall width of the trailer.3 Discussion We now turn to your inquiry. As an initial matter, it is immaterial to this analysis that the lamp is intended to illuminate only on the trailer owners’ property. NHTSA’s longstanding position is that when the vehicle is designed to be used on-road, its equipment must meet all applicable FMVSS.4 Your lamp is not required equipment and so would be considered, as you correctly describe it, as auxiliary or supplemental lighting. Therefore, we turn to the question of impairment and look to the relevant characteristics.5 The factors most relevant to your inquiry are the location and color of the lamps, which we analyze together. We find that the lamp design described in your letter is likely to impair the effectiveness of the identification and clearance lamps required by FMVSS No. 108, and, if installed by you or another entity subject to the “make inoperative” prohibition as aftermarket equipment, would impair the effectiveness of that required lighting installed in compliance with FMVSS No. 108. By requiring different colored lamps on the front and the rear of trailers, FMVSS No. 108 facilitates rapid recognition by road users of the direction that a trailer is facing or is moving. Because your device illuminates red in the front of the trailer, it operates contrary to this standard’s intention. This lighting arrangement could cause drivers to mistake the front of the trailer for the rear. Such a mistake, even if only for a moment, may cause drivers to take unnecessary, and possibly unsafe, driving maneuvers or to fail to take other maneuvers in time to 3 FMVSS No. 108 Table I-a. We hope you find this information helpful. If you have further questions, please contact Eli Wachtel of my staff at (202) 366-2992. Sincerely, Dated: 11/6/24 |
2024 |
ID: NCC-231206-001 - Steptoe VanHool FMVSS 217 Emergency Exit Requirements 11-25-2024 signedOpenNovember 25, 2024 David H. Coburn Steptoe LLP 1330 Connecticut Avenue, NW Washington, DC 20036-1795
Dear Mr. Coburn: This responds to your letter dated December 5, 2023, on behalf of Belgium-based bus manufacturer Van Hool NV regarding the emergency exit identification requirements under 49 C.F.R. § 571.217 S5.5.1 for buses other than school buses. You asked whether the requirements under S5.5.1 to designate emergency exits and provide concise operating instructions for these exits may be satisfied by pictograms, without the use of text. This letter responds to that request. In responding, the National Highway Traffic Safety Administration (NHTSA) notes that the contents of this letter do not have the force and effect of law and are not meant to bind the public in any way. This letter is only intended to provide clarity regarding existing requirements under the law at the time of signature. Section 5.5.1 requires in pertinent part: For buses other than school buses…each emergency exit door shall have the designation “Emergency Door” or “Emergency Exit,” and every other emergency exit shall have the designation “Emergency Exit” followed by concise operating instructions describing each motion necessary to unlatch and open the exit, located within 16cm of the release mechanism. S5.5.1 provides explicit designation requirements. The use of quotations in the standard indicates that the exact words “Emergency Door” or “Emergency Exit” are necessary for compliance and that a pictogram by itself will not suffice. Thus, a pictogram may not be provided in lieu of text. This position aligns with NHTSA’s earlier interpretation in Letter to Vincent P. Schulze (June 22, 1998).1 With regard to the “concise operating instructions” required by the standard, S5.5.1 does not set forth explicit language that must be used, nor does it otherwise expressly prohibit the use of pictograms, symbols, icons or similar. The standard requires only that the instructions “describ[e] each motion necessary to unlatch and open the exit.” It further provides examples of operating instructions as follows: “(1) Lift to Unlatch, Push to Open; and (2) Lift Handle and Push out to Open.” 1 Available at www.nhtsa.gov/interpretations/17175drn (declining the use of a symbol in lieu of words for emergency egress windows). While the text examples provided in the standard are not exhaustive given the breadth of variation in vehicle emergency exit design, NHTSA emphasizes the need to ensure that passengers can quickly access both the emergency exit and the instructions for the exit’s release mechanism. The agency has noted that “[i]n an emergency, persons are used to finding an emergency exit where they see a label with the designation ‘Emergency Exit.’”2 Moreover, the standard “nowhere draws any distinction between markings designating an exit as an emergency exit and markings setting forth operating instructions for the emergency exit.”3 This interpretation suggests that both the emergency exit designation and the operating instructions were intended to be text-based. Diluting the emergency egress marking requirements would be consequential to motor vehicle safety.4 At present, the agency has no data to support that a particular set of pictograms5 will be easily and universally understood by bus passengers in the United States. That U.N. Regulation No. 1076 allows for safety sign pictograms and has been accepted in the European Union7 does not inform or guarantee that an American audience will understand and accept the same pictograms. As you acknowledged, NHTSA intends its policies to both promote international harmonization and avoid unnecessary design restrictions. If a manufacturer wishes to produce vehicles with pictorial emergency egress markings not currently permitted under Standard 217, it may elect to file a petition for rulemaking on the issue. I hope this information is helpful. If you have any further questions, please feel free to contact Evita St. Andre of my staff at this address or (617) 494-2767. Sincerely,
Dated: 11/25/24 2 Letter to John G. Sims (Jan. 26, 1990), available at www.nhtsa.gov/interpretations/nht90-124. |
2024 |
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.