ID: NJP Engineering Letter of Interpretation FMVSS No. 121signed

October 4, 2024

Mr. Nick Paulick, PE
Owner, NJP Engineering, LLC
P.O. Box 2161
Oshkosh, WI 54903 

Dear Mr. Paulick, 

This responds to your letter, dated October 31, 2022, regarding removing the third axle from a used three axle semitrailer and reducing both the trailer’s load-carrying capacity and its braking capacity. More specifically, we understand you to be asking whether the reduction in braking capacity would violate the “make inoperative” prohibition in 49 U.S.C. § 30122 with respect to Federal motor vehicle safety standard (FMVSS) No. 121, Air Brake Systems. 

Please 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. 

In your letter, you stated that you are requesting an interpretation regarding the modification of semi-trailers after first sale to add or remove axles to change their load-carrying capacity and the overall capacity of a combination motor vehicle. You note that you reviewed existing interpretations (specifically, our letter to John Paul Barber on May 24, 1993) and believe that the National Highway Traffic Safety Administration (NHTSA) “is not opposed” to aftermarket modifications such as removing an axle, “so long as they are done properly and that an explanatory label is affixed, advising the user of what these changes will mean in terms of gross weight rating.” 

You ask about the specific example of a three-axle semi-trailer with each axle having a gross axle weight rating (GAWR) of 20,000 pounds and the trailer having a gross vehicle weight rating (GVWR) of 75,000 pounds. You suggest the removal of one axle from the trailer, reducing its GVWR to 65,000 pounds. You further state that a “dataplate” would be permanently affixed to the modified trailer advising the user of the revised payload capacity. Because removing an axle from the trailer also removes the brakes associated with it, you ask whether the reduced “braking capacity” of the trailer would bring the vehicle out of compliance with NHTSA’s braking standards and potentially violate the “make inoperative” prohibition. For the purposes of this letter of interpretation, we understand “braking capacity” as used in your letter to mean the ability of the vehicle to meet the stopping distance requirements in FMVSS No. 121. 

By way of 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. 

Your letter indicates that the modifications occur after first sale other than for resale.1 As you correctly note, the only legal requirement that is imposed on entities that make modifications to used vehicles is that a manufacturer, distributor, dealer, rental company, or motor vehicle repair business may not knowingly make inoperative any part of a device or element of design installed in furtherance of compliance with an applicable motor vehicle safety standard. 49 U.S.C. § 30122(b). A modifier subject to this prohibition must therefore ensure that the vehicle’s brakes and other systems remain in compliance with all applicable Federal motor vehicle safety standards once the modifications are performed. Civil penalties can be imposed under 49 U.S.C.
§ 30165(a) for violations of section 30112(b). 

We assume, for the purposes of this letter, that the trailer you intend to modify is equipped with an air brake system. FMVSS No. 121 establishes requirements for vehicles equipped with air brake systems. Under S5.3.1 of FMVSS No. 121, truck tractors must meet the stopping distance requirements specified in Table II of that standard, when loaded to their GVWR and tested using an unbraked control trailer.2 We note, however, that such requirements are applicable to the truck tractor. FMVSS No. 121 contains no stopping distance requirements applicable to trailers. FMVSS No. 121 does contain other requirements applicable to trailers, such as parking brakes, and certain as-equipped requirements should the trailer axles have brakes, such as that the braked trailer axles be equipped with anti-lock braking systems and have the required air reservoirs. 

We also assume for the purposes of this letter that the entity performing the modifications is subject to the “make inoperative” prohibition. You state that NJP Engineering provides engineering services for the evaluation of new and modified cargo tank motor vehicles. From this description, it is not clear what role NJP Engineering has in the actual performance of any modifications. We also note that even if an entity not subject to the “make inoperative” prohibition modifies the vehicles, such modifications may be subject to the laws and regulations administered by the Federal Motor Carrier Safety Administration and the States in which the vehicles are operated.

1 Because the trailer is a used trailer, you are not an alterer. An alterer is defined as a person who alters by addition, substitution, or removal of components (other than readily attachable components) a certified vehicle before the first purchase of the vehicle other than for resale. 49 C.F.R. § 567.3.
2 The following vehicles may meet the stopping distance requirements specified in Table IIa instead of Table II: Three-axle tractors with a front axle that has a GAWR of 14,600 pounds or less, and with two rear drive axles that have a combined GAWR of 45,000 pounds or less, that were manufactured before August 1, 2011; and all other tractors that were manufactured before August 1, 2013. For such vehicles, the analysis in this letter of interpretation is the same. 

In your letter, you state that a three-axle trailer would be modified to remove an axle and you ask about the applicability of the “make inoperative” prohibition with respect to the trailer’s braking capacity. FMVSS No. 121 does not contain stopping distance requirements applicable to trailers. Therefore, a reduction in braking capacity alone would not affect compliance with the FMVSSs and would not violate the “make inoperative” prohibition.3 Regarding other braking performance requirements applicable to trailers, such as parking brake requirements and as- equipped requirements for trailer axles, modifications to the trailer as stated must not take the trailer out of compliance with requirements that would be applicable to the modified trailer. You do not ask about, nor does this letter address, any other aspect of compliance with FMVSS No. 121, or other applicable FMVSS. 

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

Sincerely,
ADAM RAVIV
Adam Raviv Chief Counsel

Dated: 10/4/24
Ref: Standard No. 121

3 You note that you intend to affix a “dataplate” indicating the revised weight capacity of the trailer. We note that such a “dataplate” is not required by our regulations; however, we believe it is appropriate to add a label to the vehicle which indicates the appropriate loaded weight of the modified vehicle in situations where certain modifications that might be made to a used vehicle (e.g., adding or deleting an axle) which could make the originally assigned GVWR inappropriate for the vehicle as modified.
 

ID: NCC-230308-001 NelsonMullinsParkingBrakeIndicatorInterp

October 31, 2024

Ms. Christie L. Iannetta
Nelson Mullins Riley & Scarborough LLP
101 Constitution Ave, NW, Suite 900
Washington, DC 20001

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
By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to ensure that their vehicles and equipment meet applicable requirements.

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
FMVSS No. 135 establishes requirements for light vehicle braking systems. Paragraph S5.5.1 of FMVSS No. 135 requires indicators to be activated when the ignition (start) switch is in the “on” (“run”) position and one or more of seven scenarios occur. Paragraph (c) of S5.5.1 requires an indicator to be activated upon “application of the parking brake.” So if the parking brake is applied and the vehicle’s ignition is in the “on” position, a parking brake indicator must be activated.

Your Question and NHTSA’s Response
In your letter, you describe a manufacturer’s Electronic Parking Brake (EPB) system. You indicate the EPB system is integrated into the rear foundation brake calipers and is not separately serviceable. Your letter states that the EPB can be applied manually by the driver or automatically by the system. When the driver manually applies the parking brake control, upon successful confirmation of engagement of the EPB, a visual indicator appears on the user interface in plain view of the driver. You state that the EPB visual indicator remains illuminated while the EPB is engaged as a reminder to the driver to manually release the parking brake before driving.

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 would be considered noncompliant under FMVSS No. 135 S5.5.1(c). Simply put, if the parking brake is applied, the parking brake indicator must be activated.

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.

Sincerely,
ADAM RAVIV
Adam Raviv Chief Counsel
 

Dated: 10/31/24
Ref: Standard No. 135

1 See FMVSS 135 S.7.12.2(b), (i), (l).
2 See FMVSS 135 S5.3.2, S6.3.5, S6.3.11.2.
3 See 87 FR 34810 (Jun. 8, 2022).
4 The only published definition your letter provides for “parking brake system” is a proposed definition, never implemented, in FMVSS No. 121, which is a separate standard for air brake systems in trucks, buses, and trailers. Your letter also argues that “[t]he driver cannot ‘apply’ the parking brake system, only the control (e.g., using a lever or button).” In fact, FMVSS No. 135 indicates otherwise: it discusses how to test the parking brake “[i]n the case of a parking brake system that does not allow application of the specified force in a single application.” S7.12.2(j).
5 49 C.F.R. § 3(b).
6 See Letter to Headley, May 30, 2002, available at https://www.nhtsa.gov/interpretations/23871jeg#:~:text=We%20noted%20that%20the%20purpose%20of%20the,wa s%20applied%20(and%20hence%20should%20be%20released; see also Letter to Selander, Apr. 29, 2002, available at https://www.nhtsa.gov/interpretations/6992.
7 See, e.g., 49 C.F.R. § 556.

ID: NCC-230120-001 571.108 Peterson Trailer Auxiliary Door Light 11.06.24 signed

November 6, 2024

Mr. Donald Lane 

Peterson Manufacturing Co. 

4200 E. 135th Street Grandview, MO 64030 

dlane@pmlights.com

Dear Mr. Lane: 

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
https://www.nhtsa.gov/interpretations/gf006332.
2 See Letter to Paul Schaye (Sept. 9, 2019), available at https://www.nhtsa.gov/interpretations/571108-ama-schaye- front-color-changing-light; See also, Letter to Kerry Legg (Oct. 19), 2006, available at https://www.nhtsa.gov/interpretations/legg1. 

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.
4 See Letter to Paul Crunk (Aug. 11, 2000), available at https://www.nhtsa.gov/interpretations/21872ztv.
5 Regarding activation pattern, NHTSA interprets FMVSS No. 108 to require that all auxiliary lamps be “steady burning,” with the sole exception being auxiliary lamps that supplement required lamps that flash, such as turn signals. For the purposes of this letter, we assume the lamps you describe would be steady burning when activated.
Before 2007, FMVSS No. 108 included an explicit requirement that, with the exception of certain types of required lamps (e.g., turn signal lamps), all lamps on a vehicle, including auxiliary lamps, must be steady burning. In 2007, NHTSA implemented an administrative reorganization of FMVSS No. 108 which, among other things, converted the blanket “steady burning” requirement (and its exceptions) into individual activation requirements for each type of required lamp. See 72 FR 68234 (Dec. 4, 2007). Although the reorganized rule no longer includes a blanket “steady burning” requirement, NHTSA stated in the preamble to the reorganized rule that its “rewrite of FMVSS No. 108 is considered administrative in nature because the standard’s existing requirements and obligations are not being increased, decreased, or substantively modified.” Moreover, NHTSA continues to believe that flashing auxiliary lamps would impair the effectiveness of required lamps by distracting or confusing other road users.

prevent dangerous events. Therefore, it would impair the effectiveness of the identification and clearance lamps required on trailers. Additionally, when the device is activated green, it may give the misimpression to road users that it is safe to proceed forward when in fact it may not be safe to do so, which would impair the effectiveness of various required lamps intended to communicate caution, such as stop lamps. Our opinion is the same regardless of whether the light uses green or red colored light sources or colored lenses. 

We hope you find this information helpful. If you have further questions, please contact Eli Wachtel of my staff at (202) 366-2992. 

Sincerely,
Adam Raviv
Chief Counsel

Dated: 11/6/24
Ref: Standard No. 108

ID: NCC-231206-001 - Steptoe VanHool FMVSS 217 Emergency Exit Requirements 11-25-2024 signed

November 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,
ADAM RAVIV
Adam Raviv Chief Counsel

Dated: 11/25/24
Ref: Standard No. 217 

2 Letter to John G. Sims (Jan. 26, 1990), available at www.nhtsa.gov/interpretations/nht90-124.
3 Id.
4 See Denial of a Petition for Forest River Inc., 86 FR 56351 (Oct. 8, 2021) (misplacement of the emergency egress labels by 9cm).
5 Van Hool submitted that NHTSA may require that pictograms used to comply with S5.5.1 adhere to either the International Organization for Standardization (ISO) standard 3864-1:2011, paragraph 6.5, or the American National Standards Institute (ANSI) standard Z535.
6 U.N. Regulation 107, “Concerning the Adoption of Harmonized Technical United Nations Regulations for Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for Reciprocal Recognition of Approvals Granted on the Basis of these United Nations,” Revision 8 (Feb. 14, 2023), available at unece.org/sites/default/files/2023-02/R107r8e.pdf
7 Framework Regulation (EU) 2018/858 of the European Parliament and of the Council (May 30, 2018), available at
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:02018R0858-20230730&qid=1699805899877

ID: NCC-241023-001TSEI-TIMA Letter of Interpretation 571.108 Flashing Amber Lights 12-13-2024.signed.

December 13, 2024

Mr. Chuck Polley

Transportation Safety Equipment Institute

c/o Grote Industries LLC

2600 Lanier Drive

Madison, IN 47250

Mr. John Freiler

Truck Trailer Manufacturers Association

7001 Heritage Village Plaza

Suite 220

Gainesville, VA 20155-3094

Dear Messrs. Polley and Freiler:

This responds to your letter requesting clarification of Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, reflective devices, and associated equipment, regarding flashing “emergency warning lights.” I apologize for the delay in responding. As used in your letter, the term “emergency warning lights” generically refers to a category of vehicle lighting equipment that consists of one or more amber-colored flashing or strobing lamps that is typically installed on certain types of slow-moving vehicles and utility vehicles (such as tow trucks, repair vehicles, or vehicles transporting oversized loads) to call the attention of other drivers to the presence of these vehicles. 

You ask that the National Highway Traffic Safety Administration (NHTSA) provide clarification of its longstanding interpretations of FMVSS No. 108 and permit original equipment installation of “emergency warning lights.” Alternatively, you ask that NHTSA issue guidance regarding the circumstances under which such lighting may be installed by vehicle manufacturers or repair businesses without violating the “make inoperative” provision of the National Traffic and Motor Vehicle Safety Act (Safety Act) (49 U.S.C. §§ 30101 et seq.). 

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. 

After carefully considering your letter, we reaffirm our previous interpretations that, under current law, “emergency warning lights” may not be installed as original equipment and that persons subject to the make inoperative provision of the Safety Act may not legally install the lamps as original or aftermarket equipment. We explain our reasoning below, based on our understanding of the information you present. 

Background 

FMVSS No. 108 specifies requirements for original and replacement lamps, reflective devices, and associated equipment. For auxiliary lamps, the primary restriction imposed by FMVSS No. 108 is in 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.” Additionally, 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 Whether there is an impairment is determined in the first instance by the manufacturer of the vehicle (or the entity installing the aftermarket lighting) when it is certified as compliant with FMVSS No. 108. NHTSA may contest such a determination if it is clearly erroneous.2 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 is made on a case-by-case basis and considers several characteristics of the auxiliary lamp, such as the brightness, color, location, and activation pattern of the lamp, to analyze whether it impairs the effectiveness of required lighting. This list of characteristics is not exhaustive and other considerations may be relevant to the analysis. NHTSA has long maintained that highway traffic safety is enhanced by the drivers’ familiarity with established lighting schemes, which enables them to instantly recognize the meaning the lamps convey and respond accordingly. NHTSA has long interpreted FMVSS No. 108 to require that all auxiliary lamps be “steady burning,” with the sole exception of auxiliary lamps that supplement required lamps that flash, such as turn signals.3 

Discussion 

NHTSA’s longstanding interpretation of FMVSS No. 108 is that the standard does not permit the “emergency warning lights” to be installed as original equipment because they are auxiliary lighting that is not steady burning and would impair the effectiveness of required lamps by causing confusion among other drivers about the meaning of required lighting or distracting drivers from required lighting.4 Further, because “emergency warning lights” would impair the effectiveness of required lamps, NHTSA has also determined that entities listed in § 30122 of the Safety Act that install “emergency warning lights” on new or used vehicles would violate the “make inoperative” provision of the Act. 

Notwithstanding those interpretations, you provide various reasons why you believe that “current regulations permit manufacturers to install such supplemental lighting as original equipment.” We respond to your reasons below. 

1 E.g., Letter to Timothy C. Murphy (Nov. 1, 2004), available at https://www.nhtsa.gov/interpretations/gf006332.
2 Letter from John Womack to Larry Grabsky (Nov. 16, 1993), available at https://www.nhtsa.gov/interpretations/9251.
3 See, e.g., Letter to Richard Seoane (June 27, 2024), available at https://www.nhtsa.gov/interpretations/ncc-231121- 001-autoliv-veoneer-spotlight-interpretation-1; and Letter to Paul Schaye (Sept. 9, 2019), available at https://www.nhtsa.gov/interpretations/571108-ama-schaye-front-color-changing-light.
4 Letter to J. Adam Krugh IV (May 22, 2003), available at https://www.nhtsa.gov/interpretations/002769drn (explaining that a flashing or strobing lamp on top of a school bus would impair the effectiveness of required signal lamps by diverting other drivers’ attention and causing confusion). 

Administrative Rewrite of FMVSS No. 108. First, you state that in an administrative rewrite of FMVSS No. 108, NHTSA removed explicit language in the standard that had contained a provision requiring that all lamps be steady burning unless otherwise indicated. You argue that the removal of this provision indicated an intention to loosen the restriction that auxiliary lamps must be steady burning when activated. 

NHTSA had no such intention. The removal of the referenced “steady burning” language in the FMVSS No. 108 administrative rewrite did not change the underlying substantive requirements that had applied to auxiliary lighting. Before it was modified in 2007, FMVSS No. 108 included an explicit requirement that, with the exception of certain types of required lamps (e.g., turn signal lamps), all lamps on a vehicle, including auxiliary lamps, must be steady burning. In 2007, NHTSA implemented an administrative reorganization of FMVSS No. 108 which, among other things, clarified the blanket “steady burning” requirement (and its exceptions) by converting it into specified individual activation requirements for each type of required lamp.5 Although the reorganized rule no longer includes a blanket “steady burning” requirement, NHTSA stated in the preamble to the reorganized rule that its “rewrite of FMVSS No. 108 is considered administrative in nature because the standard’s existing requirements and obligations are not being increased, decreased, or substantively modified.”6 Further, NHTSA continues to believe that flashing auxiliary lamps would impair the effectiveness of required lamps by distracting or confusing other road users and we have continued to restrict flashing or strobing auxiliary lamps since the rewrite except under a few limited circumstances not relevant here.7 Therefore, because the “emergency warning lights” are not steady burning, they would not comply with FMVSS No. 108 and would impair required lighting. 

Motorists are Used to “Emergency Warning Lights.” Second, you state that one of NHTSA’s reasons for disallowing flashing auxiliary lamps—their tendency to divert attention and cause confusion—is no longer valid for “emergency warning lights” because “the use of flashing-amber lighting has become widespread.” You provide no data or information to support this assertion, except to refer to past agency letters which discussed the make inoperative provision as applied to owners installing flashing or strobe lamps on their own vehicles, including a state installing the lamps on state-regulated emergency vehicles. 

We disagree with your assertion that the letters are indicative of the pervasiveness of “emergency warning lights.” The interpretation letters to which you refer do not endorse the installation of flashing or strobe lamps by individuals or declare that the lights do not impair the effectiveness of required lamps. Rather, those letters simply recognize the limits of NHTSA’s authority under the Safety Act to regulate aftermarket lighting equipment. The agency made, and continues to make, no determination as to whether the flashing amber lights are “widespread.”

5 72 FR 68234 (Dec. 4, 2007).
6 Id.
7 These exceptions include auxiliary lamps that supplement required flashing lamps like turn signals. See Letter to Jerry Koh (Feb. 6, 1986), available at https://www.nhtsa.gov/interpretations/86-250; see also Letter to Lt. Col. Steve Flaherty (May 2, 2003), available at https://www.nhtsa.gov/interpretations/flaherty (deference to states applies to “the installation and use of emergency lighting devices on [undercover state police] vehicles”). 

NHTSA has long believed that flashing amber lighting can unduly divert driver attention and cause confusion among drivers, even among those who have seen them before. As we have stated, “traffic safety is enhanced by the familiarity of drivers with established lighting schemes, which facilitates their ability to instantly and unhesitatingly recognize the meaning lamps convey and respond to them.”8 Flashing amber lighting, except for turn signal lamps, is not “an established lighting scheme” within the context of FMVSS No. 108. The meaning of flashing lights can vary depending on the nature of the vehicle on which they are installed, the context in which they are used, and state or local laws. Motorists might not know if the flashing amber lamps are meant to signal the presence of the vehicle for general driver awareness or the need for drivers to yield the right-of-way or perform some other driving task. The use of flashing amber lights is not sufficiently established and standardized to avoid unduly diverting driver attention or causing confusion. Thus, we continue to believe these lights impair required lighting equipment.9 

Other Federal Regulations and State Laws Recognizing “Emergency Warning Lights.”
Finally, you argue that permitting flashing amber auxiliary lamps as original equipment would “harmonize” NHTSA’s requirements with Federal Motor Carrier Safety Administration (FMCSA) regulations and state laws. You state that an FMCSA regulation (49 C.F.R. § 393.25(e)) permits the use of flashing lights on several vehicle types and that a change in NHTSA’s approach would better ensure such lighting is properly wired and installed. We are also aware of exemptions granted by FMCSA permitting certain entities to use pulsating brake-activated amber lights as well as the operation of commercial motor vehicles equipped with the Intellistop device.10 

Our longstanding interpretation of FMVSS No. 108 regarding flashing auxiliary lights is not impacted by these FMCSA regulations, exemptions, or state laws. The FMCSA regulation does not require the flashing lamps to be installed as original equipment or by an entity subject to the make inoperative provision. Additionally, although you allude to safety concerns about owners improperly wiring or installing emergency warning lights on their vehicles to comply with state laws, we are not aware of any state laws requiring installation of these lights specifically as original equipment or by an entity subject to the make inoperative requirement. Nor is allowing installation by such entities necessary to address improper owner installations of these lights. 

If you have further questions, please contact Eli Wachtel of my staff at (202) 366-2992.

Sincerely,
ADAM RAVIV
Adam Raviv Chief Counsel
 

Dated:12/13/24
Ref: Standard No. 108

8 Letter to J. Adam Krugh IV (May 22, 2003), available at https://www.nhtsa.gov/interpretations/002769drn.
9 Nothing in this letter is intended to conflict with our interpretation, stated in our May 2, 2003, Letter to Lt. Col. Steve Flaherty, that deference to states applies to “the installation and use of emergency lighting devices on [the state’s] vehicles.” Letter available at https://www.nhtsa.gov/interpretations/flaherty.
10 List of FMCSA exemptions in effect available at https://www.fmcsa.dot.gov/exemptions.

ID: NCC-220915-001 Speedometer Conformity Interp Letter

March 21, 2023

Chris Cowen
Port Intelligence Officer
Customs and Border Protection Tactical Operations
104 Bridge Approach Plaza
Ogdensburg, NY 13669 

Dear Mr. Cowen: 

This responds to your email to the National Highway Traffic Safety Administration (NHTSA) requesting a determination as to whether certain vehicles imported into the United States from Canada comply with applicable Federal Motor Vehicle Safety Standards (FMVSS) relating to speedometers. Specifically, you ask whether vehicles equipped with both an analog speedometer that displays only in kilometers per hour (km/h) and a multifunction display that is capable of displaying in miles per hour (MPH) if the driver selects that option would be permissible for importation into the United States without modification. 

Based on the requirements of FMVSS No. 101, Controls and displays, the answer is no. These vehicles do not conform to NHTSA’s requirements and thus are not eligible for importation without modification. Please note that our answer is based on our understanding of the specific information provided in your email. 

Background 

The National Traffic and Motor Vehicle Safety Act of 1966 (Safety Act, 49 U.S.C. Chapter 301) authorizes NHTSA to issue safety standards applicable to motor vehicles and items of motor vehicle equipment. However, NHTSA does not approve motor vehicles or motor vehicle equipment. Instead, the Safety Act establishes a self certification process under which each manufacturer is responsible for certifying that its products meet our safety standards. This agency periodically tests vehicles and equipment items for compliance with the standards and investigates alleged safety-related defects. 

Page 2
Mr. Chris Cowen 

Of relevance to your request, NHTSA issued Federal Motor Vehicle Safety Standard No. 101 (49 CFR § 571.101), which primarily ensures the accessibility, visibility, and recognition of motor vehicle indicators, including speedometers, to reduce safety hazards caused by diversion of the driver’s attention. This standard specifies performance requirements for location, identification, color, and illumination of motor vehicle indicators. It applies to passenger cars, multipurpose passenger vehicles, trucks, and buses. 

Discussion 

The questions inherent in your request, as we understand it, are below:  

1. Do the speedometers meet the FMVSS No. 101 definition of an indicator?  
2. If so, does each indicator meet the requirements of FMVSS No. 101? 

Regarding the first question, paragraph S4 of FMVSS No. 101 defines an indicator as “a device that shows the magnitude of the physical characteristics that the instrument is designed to sense.”  Table 1 of FMVSS No. 101 specifies that speedometers are, in fact, indicators. 

Regarding the second question, paragraph S5 of FMVSS No. 101 states that all covered vehicles fitted with indicators listed in Table 1 must meet the requirements for the location, identification, color, and illumination of those indicators. 

Based on our review of the photographs you provided, the speedometers at issue appear to satisfy the requirements for location and color, in accordance with paragraph S5.1 “Location” and paragraph S5.4 “Color.”  

We now turn to the identification requirement. Table 1 specifies that speedometers must be identified with units of measurement, using either “MPH” or “MPH and km/h.” You provided pictures of two speedometers: an analog gauge displaying only metric units (km/h) and a digital display that allows the driver to select U.S. customary units (MPH). The analog gauge clearly does not meet the identification requirement of Table 1 because it is marked only in km/h. Next, we consider whether the digital display, defined as a multi-task display in paragraph S4 of FMVSS No. 101, meets the requirement. A multi task display is a display on which more than one message can be shown simultaneously. For example, the display here reportedly presents a layered menu of functions that the driver can change. If the driver selects the digital “MPH” display, the speedometer appears to meet the requirements of FMVSS No. 101. If, however, the driver selects a different menu option (or no menu option), the speedometer no longer displays “MPH.” Therefore, the multi-task display, by itself, does not meet the identification requirement that “MPH” always be displayed, and in the absence of an analog speedometer that displays MPH, this vehicle would not be compliant with FMVSS No. 101.  

We have not evaluated the “illumination” requirement, as your correspondence does not provide sufficient information to allow us to do so. 

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Mr. Chris Cowen 

In sum, an indicator, including a speedometer, must meet all requirements of FMVSS No. 101. For the reasons enumerated above, the requirements of the FMVSS are not met and the vehicles are noncompliant. Therefore, vehicles containing these instruments are not eligible for importation into the United States without modification. 

I hope this information is helpful. If you have any further questions, please feel free to contact Terrence Sommers of my staff at this address or at terrence.sommers@dot.gov.  

Sincerely,

John Donaldson
Acting Chief Counsel

Dated: 3/23/23
Ref: Standard No. 101

ID: NCC-230816-001 Antolin Sun Visor

May 17, 2024

Dr. Enrique Curiel Sanz
Passive Safety Manager – Engineering Shared Services
Grupo Antolin
Enrique.curiel@grupoantolin.com 

Dr. Curiel Sanz, 

This responds to your email to the National Highway Traffic Safety Administration (NHTSA) concerning the standards that sun visors must meet under the Federal Motor Vehicle Safety Standards (FMVSS). Your question concerns evaluation of sun visors, specifically how NHTSA determines if the sun visor is covered in an energy absorbing material. Please note that our answer below is based on our understanding of the specific information provided in your email. 

Background 

NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act, 49 U.S.C. Chapter 301) to issue federal motor vehicle safety standards (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. 

In your July 19, 2023 message, you asked about the evaluation criteria for sun visors. Specifically, you asked whether sun visors are tested with a pendulum to determine if they are made of an energy absorbing material, and if so, which criteria are used to determine whether the sun visor passes or fails the test. On July 24, 2023, NHTSA responded to your message, indicating that the sun visor requirements in FMVSS No. 201 require that the visor be constructed of or covered with energy absorbing material and that each sun visor mounting present no rigid material edge radius of less than 3.2 mm that is statically contractable by a spherical 165 mm diameter head form. Thereafter, you requested clarification as to how a manufacturer may confirm that a visor’s material meets the definition of “energy-absorbing,” such as material composition or testing under impact conditions. 

Discussion 

As explained, under the Safety Act, each manufacturer of a motor vehicle or item of motor vehicle equipment is responsible for certifying that its products meet all applicable safety standards. Given
 

1 49 U.S.C. 30115. 

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Dr. Enrique Curiel Sanz 

this “self-certification” regime, NHTSA does not certify or approve motor vehicles or motor vehicle equipment for compliance with the FMVSS. Manufacturers may not certify a vehicle or item of motor vehicle equipment if, “in exercising reasonable care, [they have] reason to know the certificate is false or misleading in a material respect.”
2 

FMVSS No. 201, “Occupant protection in interior impact,”3 establishes performance requirements designed to reduce the risk of injury in the event an occupant strikes the interior of a vehicle during a crash. Paragraph S5.4 of the standard requires that sun visors be “constructed of or covered with energy-absorbing material” and that the visor’s mounting must “present no rigid material edge radius of less than 3.2 mm that is statically contactable by a spherical 165 mm head form.” The purpose of this requirement is to reduce the injuries that occur when occupants strike the visor or visor mounting with their heads.  

The standard does not further define “energy-absorbing.” Moreover, neither the standard nor NHTSA’s own test procedure4 provides a performance-based or material definition of energy-absorbing, or a test for measuring the energy-absorption capability of sun visor material. Further, the laboratory test procedure for assuring compliance with the standard requires only that the sun visor be made of an energy-absorbing material; no further guidance is provided. Therefore, the responsibility is with the manufacturer to self-certify that the material from which sun visors are constructed or with which they are covered is energy-absorbing to meet the requirements of this standard. 

In so doing, please note that in addition to meeting the S5.4 requirements, S4.2 dictates that vehicles must also comply with the requirements of S6. S6.1.4.2 in turn requires that new vehicles meet the performance standards set forth in S7. Therefore, in addition to the requirement that sun visors be constructed of or covered in an energy absorbing material, manufacturers of sun visors must construct them in such a manner as to ensure compliance with the performance standard of S7 when installed in a vehicle. Compliance with S7 will ensure that the sun visors meet the performance standard, which is what NHTSA requires, along with ensuring that all components are free of safety defects. 

I hope this information is helpful. If you have any further questions, please feel free to contact Terrence Sommers of my staff at the address above or at (202) 366-7577. 

Sincerely,
Adam Raviv
Chief Counsel
 

2 Id.
3 Available at https://www.govinfo.gov/content/pkg/CFR-2022-title49-vol6/pdf/CFR-2022-title49-vol6-sec571-201.pdf (last accessed May 16, 2024).
4 Available at https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/tp-201-02a_tag.pdf (last accessed May 16, 2024).

Dated: 5/17/24
Ref: Standard No. 201

ID: Interpretation-ElectraMeccanica-May 22 2024

May 22, 2024

Mr. Isaac Moss
Chief Administration Officer
ElectraMeccanica
EMV Automotive USA, Inc.
11647 Ventura Blvd.
Studio City, CA 91604 

Dear Mr. Moss: 

This letter responds to your request, on behalf of the ElectraMeccanica Automotive USA, Inc., for guidance as to whether passenger car tires certified to meet Federal Motor Vehicle Safety Standard (FMVSS) No. 139 may be installed on new motorcycles. 

Your letter references a December 30, 1982 interpretation letter confirming that paragraph S5.1.1 of FMVSS No. 120 permitted a motorcycle to be equipped with passenger tires certified as complying with FMVSS No. 109, as long as the tires were fitted to rims listed as suitable for use with the equipped tires, and as long as those rims met the marking requirements of FMVSS No. 120.1 You note that since this 1982 interpretation letter, FMVSS No. 120 has been revised. Although you do not note this in your letter, since 1982, the National Highway Traffic Safety Administration (NHTSA) has substantially updated tire requirements and new passenger car tires are now required to meet FMVSS No. 139. You ask three questions in your letter, and I will address each in turn. 

First, you ask whether NHTSA can expand its December 30, 1982 interpretation letter to include passenger cars meeting the requirements of FMVSS No. 139. I can confirm for you that FMVSS No. 120 allows new motorcycles to be equipped with tires certified to meet FMVSS No. 139. This is explicitly stated in paragraph S5.1.1 of FMVSS No. 120. 

Second, you ask whether NHTSA can confirm that NHTSA would reference S4 of FMVSS No. 139, in lieu of the references to S4.4 of FMVSS No. 109 and S5.1 of FMVSS No. 119 

1 Letter to Anonymous (Confidential) (Dec. 30, 1982), available at https://www.nhtsa.gov/interpretations/1982-337  

Page 2
Mr. Isaac Moss 

contained in S5.1.1 of FMVSS No. 120. The answer to this question is yes. If tires certified to meet FMVSS No. 139 are installed on a new motorcycle, the tire manufacturer must list the rims as suitable for use with those tires in accordance with S4 of FMVSS No. 139. This requirement is consistent with the tire and rim matching information for tires certified with FMVSS Nos. 109 or 119. S4 of FMVSS No. 139, like S4.4 of FMVSS No. 109 and S5.1 of FMVSS No. 119, provides for disclosure of the rims that may be used with each tire a manufacturer produces. The tire’s manufacturer may make this disclosure either in a specific document provided to dealers of the manufacturers’ tires and to NHTSA, or in a yearbook published by one of several tire and rim standards organizations. 

Third, you ask whether NHTSA can provide guidance on whether compliance with FMVSS No. 110 is required in addition to FMVSS No. 120 when tires certified to meet FMVSS No. 139 are used on motorcycles. The answer to this question is no. FMVSS No. 110 is not applicable to motorcycles, even if tires meeting FMVSS No. 139 are installed on motorcycles. S2 of FMVSS No. 110 explicitly excludes motorcycles from the applicability of FMVSS No. 110. The only tire selection and rim standard applicable to motorcycles is in FMVSS No. 120. 

I hope this information is helpful. If you have any further questions, please feel free to contact David Jasinski of my office at (202) 366-2992. 

Sincerely,
Adam Raviv
Chief Counsel

Dated: 5/22/24
Ref: Standard No. 139

ID: 571.108 School Bus Focused Illuminated Projection Lanyon NCC-230125-001

March 21, 2023

Mr. Bobby Lanyon
Access Innovations Global LP dba AIG Safety
PO Box 511
Orefield, PA 18069 

Dear Mr. Lanyon,  

This letter responds to your request that the National Highway Traffic Safety Administration (NHTSA) allow, but not mandate, your company’s product, the “Focused Illuminated Projection” system, for application on school buses under Federal Motor Vehicle Safety Standard (FMVSS) No. 131, School bus pedestrian safety devices. Your request was referred to my office to determine whether the feature you describe is allowed under existing FMVSSs. While you asked for an amendment to FMVSS No. 131, we believe it is appropriate to consider whether your product would be permitted as an auxiliary lighting device under FMVSS No. 108, Lamps, reflective devices, and associated equipment. Based on the information you have provided, our answer is that your device is permissible under FMVSS No. 108 for the reasons explained below. 

By way of background, NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to self-certify that their products conform to all applicable FMVSSs that are in effect on the date of manufacture before the products can be offered for sale. Manufacturers must also ensure their products are free of safety-related defects. This letter represents NHTSA’s opinion concerning whether your product, as you describe it, would be permitted under FMVSS No. 108. It is not an approval of your product, nor is it an endorsement of the safety claims made in your interpretation request.  

Under FMVSS No. 108 S6.2.1, non-required additional lamps are prohibited on new
vehicles if they impair the effectiveness of lighting devices required by FMVSS No. 108. The question as to whether an auxiliary lamp impairs required lighting equipment is usually decided on a case-by-case basis.1 Based on the information you have provided, we have concluded that the “Focused Illuminated Projection” system will not impair the effectiveness of a school bus’s required lighting. 

1 Letter to Michael Haas (May 6, 2019), available at https://isearch.nhtsa.gov/files/571.108%20--%20HDC%20Supplemental%20Turning%20Lamps%20--%20HAAS%20--%2015-4155.htm. 

Page 2
Mr. Bobby Lanyon 

Description of the “Focused Illuminated Projection” system 

Your letter describes the system as a “low technology, high reliability solution designed and implemented to re-enforce the explicit and implied scope (S1) and Purpose (S2) of Section 571.131 by statically illuminating the 10ft stopping threshold” onto the roadway in front of and behind a school bus during a school bus stop. AIG also describes it as creating an “illuminated crosswalk” for students. 

The system consists of red LED lights mounted onto the front and rear of the bus adjacent to or below the signal warning lamps above the front windshield or rear window. It projects a red line onto the road 10 feet in front of and behind the bus. It is controlled by the “same electrical relay that illuminates” the lamps on the stop signal arm. We assume, for the purposes of this interpretation, that this device only activates when the vehicle is stopped and is in a loading/unloading state, when the stop arm is also activated or the door is open. 

Discussion 

FMVSS No. 108 requires that school buses be equipped with a system of two red signal lamps, and optionally two amber signal lamps, installed at both the top front and top rear. These lamps must flash alternately at a rate of 60-120 cycles per minute. We have previously stated that auxiliary lamps can impair the effectiveness of required lighting in four ways: brightness, activation pattern, color, and mounting location.2 

Brightness will cause impairment if the additional lamp is so bright as to obscure or distract from required lighting. Based on the photographs provided in your submission, it does not appear that your device would cause impairment of a school bus’s required lighting due to brightness. Additionally, because your device is a projection system, brightness concerns, particularly at a distance, are mitigated by the ability to apply a shade to the device to ensure that only the projected image is visible.  

Regarding activation pattern, FMVSS No. 108 requires all auxiliary lamps, with the exception of certain specified types of lamps such as turn signal lamps, to be steady burning.3 You state that the “Focused Illuminated Projection” is “statically illuminating” 

2 Letter to Paul Schaye (September 9, 2019), available at https://isearch.nhtsa.gov/files/571.108%20--%20AMA%20--%20Schaye--front%20color%20changing%20light.htm. 
3 Prior to 2007, FMVSS No. 108 included an explicit requirement that, with the exception of certain types of required lamps (e.g., turn signal lamps), all lamps on a vehicle, including auxiliary lamps, must be steady burning. In 2007, NHTSA implemented an administrative reorganization of FMVSS No. 108 which, among other things, converted the blanket steady burning requirement (and its exceptions) into individual activation requirements for each type of required lamp. See 72 FR 68234 (Dec. 4, 2007). Although the reorganized rule no longer includes a blanket steady burning requirement, NHTSA stated in the preamble to the reorganized rule that its rewrite of FMVSS No. 108 is considered administrative in nature because the standard’s existing requirements and obligations are not being increased, decreased, or substantively modified. Moreover, NHTSA continues to believe that flashing auxiliary lamps would impair the effectiveness of required lamps by distracting or confusing other road users. See Id., at FN 7. 

Page 3
Mr. Bobby Lanyon 

the stopping threshold in front of and behind the bus, which we understand to mean that the device is steady burning. Therefore, your device’s activation pattern is unlikely to distract other road users from the required lighting and will not impair the effectiveness of the vehicle’s required lighting due to activation pattern. 

Regarding color, NHTSA has stated that impairment concerns prohibit the use of lamps of colors that are likely to cause confusion to other road users.4 For example, NHTSA has previously stated that red lamps placed on the front of non-school-bus vehicles impair the effectiveness of lighting required under FMVSS No. 108 because drivers understand red to mean stop and those lamps can be confused with stop lamps.5 However, this is not necessarily the case with school buses because they are required to have red signal warning lamps on the front of their cabs. Here, the question is whether your device would impair a school bus’s required lighting, in particular the red signal warning lamps that are required on the front and rear of school buses. The purpose of the signal warning lamp is to “identify a vehicle as a school bus and to inform other users of the highway that such vehicle is stopped on the highway to take on or discharge school children.”6 Your device is designed to increase the conspicuity of a stopped school bus and benefit that purpose. It supplements the signal warning lamp by activating only while the required red signal lamp is activated, which occurs when the bus is in a stopped and loading/unloading state. This matches the purpose of the red signal lighting. In addition, nearby drivers are likely to understand the red indicator to mean “stop” and “do not enter the projected zone,” which may further the purpose of the required signal lamps. Therefore, it is our opinion that it is unlikely to impair the effectiveness of lamps required by FMVSS No. 108 due to color. 

Regarding mounting location, lamps impair the effectiveness of required lighting under FMVSS No. 108 if they are mounted in locations that cause them to interfere with the ability of a vehicle’s required lamps to achieve their purpose.7 Generally, we have found that this requires auxiliary lighting to be mounted “far enough away” from other lamps that it does not impair their effectiveness.8 Although your device is mounted adjacent to or just below the signal warning lamps, your device’s mounting location is not likely to impair the signal warning lamps because your device is a projection system. At distance, especially if there is a shade on the device, other road users are unlikely to observe any interference with the signal lamp. 

Previously, we have found that certain auxiliary stop signal lamps on school buses were likely to impair the effectiveness of required lighting under FMVSS No. 108. For example, we found the ALLSTOP system, a red flashing light affixed to the roof of a 

4 Letter to Paul Schaye (September 9, 2019), available at https://isearch.nhtsa.gov/files/571.108%20--%20AMA%20--%20Schaye--front%20color%20changing%20light.htm. 
5 Id.
6 49 CFR 571.108 S4.
7 Letter to Paul Schaye (September 9, 2019), available at https://isearch.nhtsa.gov/files/571.108%20--%20AMA%20--%20Schaye--front%20color%20changing%20light.htm.  
8 See, e.g., Letter to Redacted (January 21, 2004), available at
https://isearch.nhtsa.gov/files/GF007705.html. 
 

Page 4
Mr. Bobby Lanyon 

school bus that only activated when the school bus door was open, “would divert a
driver’s attention from the required signal lamps and cause confusion with respect to their meaning….”9 Your device is distinguishable from the ALLSTOP and is unlikely to cause confusion with the signal warning lamp for two reasons: first, it is steady burning, and second, the meaning of your device’s signal appears to be unambiguous. The ALLSTOP had a much higher likelihood of distracting or confusing drivers because it was a flashing and rotating device like a police light. NHTSA has found impairment where it is likely that an auxiliary or alternative lighting scheme could confuse drivers due to an ambiguous meaning.10 For example, NHTSA recently stated that the HELP system, which flashed the turn signal lamps to create an additional hazard warning system, had an ambiguous meaning if used in any situation other than while parked.11 Your device, however, as two static projected red lines on the road, plainly indicates “do not enter.” Therefore, it is our opinion that your device is unlikely to impair the effectiveness of the required lighting under FMVSS No. 108 and is permissible under that standard.  

With respect to the aftermarket, 49 U.S.C. 30122 has the effect of requiring that the installation of any aftermarket vehicle lamp, by a manufacturer, distributor, dealer, or motor vehicle repair business, must not “make inoperative” any element of design or device installed on a vehicle in accordance with FMVSS No. 108. As with original equipment, we regard the addition of a projection lamp that is used in the way we understand your “Focused Illuminated Projection” system to operate not to make inoperative a vehicle’s original required lighting equipment. 

If you have further questions, please contact Eli Wachtel of my staff at (202) 366-2992. 

Sincerely, 

John Donaldson
Acting Chief Counsel
 

9 Letter to J. Adam Krugh (May 22, 2003), available at https://isearch.nhtsa.gov/files/002769drn.html. 
10 Letter to Steven T. Powers (January 19, 2021), available at https://isearch.nhtsa.gov/files/571.108--HELP%20System--Powers.htm. 
11 Id. 

Dated: 3/21/23
Ref: Standard No. 131

ID: NCC-211019-002 Zorn VW EPB FMVSS 135 2024.05.31_Interp

May 31, 2024

Mr. Thomas Zorn 

Vice President 

Vehicle Safety Office 

Volkswagen Group of America 

2200 Woodland Pointe Ave. 

Herndon, VA 20171 

Dear Mr. Zorn: 

This interpretation responds to your letter asking whether Volkswagen’s new Electronic Parking Brake (EPB) system complies with Federal Motor Vehicle Safety Standard (FMVSS) No. 135, Light vehicle brake systems. Specifically, you asked (1) whether paragraph S5.2 of FMVSS No. 135 would permit an EPB system that uses a traditional friction brake combined with a mechanical drivetrain lock; and (2) whether Volkswagen may rely on the entire EPB system for compliance with the test set out in paragraph S7.12. Based on the information you have provided, our answer to both of your questions is yes. 

By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide advance approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to ensure that their vehicles and equipment meet applicable requirements. The following represents our opinion based on the facts provided in your letter. 

In addition, 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. 

Paragraph S5.2 of FMVSS No. 135 provides: “Each vehicle shall be equipped with a parking brake system of a friction type with solely mechanical means to retain engagement.” The term “parking brake” is defined in 49 C.F.R. Part 571.3(c) as “a mechanism designed to prevent the movement of a stationary motor vehicle.” Thus, a compliant parking brake must prevent movement of a stationary motor vehicle by means of friction. Additionally, the parking brake system must also have “solely mechanical means to retain engagement,” meaning it cannot be held in place by non-mechanical means such as fluid, air, or electricity. 

Paragraph S7.12.2 of FMVSS No. 135 describes NHTSA’s conditions and procedures for testing whether a parking brake system complies with our standard. The test procedures require a test conductor to, among other things, drive the vehicle onto a 20 percent grade, apply the 

Mr. Thomas Zorn 

Page 2 

service brake with enough force to hold the vehicle stationary, shift the transmission into neutral, engage the parking brake system, and remove all force from the service brake. After the test conductor has taken the above steps, the vehicle must then remain stationary for five minutes. If the vehicle remains stationary for the required five minutes, the test conductor then repeats the test with the vehicle facing in the opposite direction on the grade. If the vehicle once again meets the stationary time requirement, and meets all other requirements in the paragraph, the parking brake system passes the compliance test.  

The EPB system described in your letter appears to be a parking brake of a friction type with solely mechanical means to retain engagement. You describe Volkswagen’s new EPB as a system that will “utilize a traditional friction brake combined with a mechanical lock that is automatically engaged in the vehicle drivetrain when the EPB is activated.” Based on this description, the system has a friction element combined with a mechanical drivetrain lock designed to hold the vehicle stationary. Additionally, based on the information provided in your letter, engagement of the friction element of the EPB is not retained by pneumatic or hydraulic means. To the best of our knowledge, the only ways to retain engagement of a friction type brake are by pneumatic, hydraulic, or mechanical means. Because your friction brake is not retained by pneumatic or hydraulic means, for the sake of this letter, we are assuming that engagement of the friction element of the EPB is retained by mechanical means.1 Applying that assumption, the Volkswagen EPB system described in your letter appears to meet the requirements of S5.2 of FMVSS No. 135. 2 

You also state that Volkswagen intends to rely on the entire EPB system to demonstrate compliance with paragraph S7.12 and ask whether NHTSA would conduct its compliance tests similarly. In conducting compliance testing for parking brakes, NHTSA follows the testing procedures set out in S7.12, as described above. You state that the friction element and mechanical lock are “designed to operate together only, and cannot be engaged individually by the vehicle operator.” Additionally, you indicate that it would be impossible for Volkswagen’s EPB system to engage the friction brake exclusively without the mechanical lock engaging. The testing procedure specified in S7.12 does not mandate a parking brake system hold a vehicle stationary by exclusively friction means. Accordingly, if NHTSA conducted compliance testing on the EPB described in your letter, it would follow the procedures as written in S7.12. 

I hope this answers 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. 

Sincerely,

ADAM RAVIV
Adam Raviv Chief Counsel

Dated: 5/31/24
Ref: Standard No. 135