ID: nht95-2.57

TYPE: INTERPRETATION-NHTSA

DATE: April 27, 1995

FROM: Mayo D. Tubbs -- Visionary Lighting Systems

TO: Philip Recht -- Acting Deputy Administrator, NHTSA

TITLE: Revised High-Technology Lighting System for the Trucking Industry

ATTACHMT: ATTACHED TO 6/9/95 LETTER FROM JOHN WOMACK TO MAYO D. TUBBS -- (A43; STD. 108)

TEXT: Dear Mr. Recht:

I was disappointed to ascertain from your correspondence dated April 13, 1995 that my color selection of Aviation Green for the strip lighting system would not conform to Standard No. 108. While I feel strongly that the unique green color would incre ase drivers' visual acuity and enhance identification of trailers in low light and inclement weather conditions, the system is not limited to the color green. Subsequent discussions with Mr. Taylor Vinson concerning the use of amber and red colored stri p lights indicate the system may comply with Standard No. 108 if these colors were utilized in lieu of green. Attachment A provides color locations of the strip lights.

Selection of the proper red and amber colors will conform to CIE 1931 and 1976 UCS Chromaticity Diagrams. Amber will be in the 580 nanometer range while red will be in the 610 nanometer range.

All other system specifications remain the same as the original design. Light output will be in the 4fL range, the system power input requirement will be less than 1 amp D.C. and the physical shape of the lights will be the same. The inherent safety f eatures of the previously submitted lighting system will apply to red and green strip lights also.

Concerning the physical locations of the strip lights and the possible interference with the conspicuity reflective tape along the sides and rear of the trailer. I understand that covering or partial obscuration of the reflectivity tape will decrease tape effectiveness and consideration will be given in selecting proper areas of strip light installation. Mr. Taylor noted that new production trailers must have the reflective tape installed at the top, rear of the trailer in accordance with S5.7. Mo st trailers provide sufficient area to accommodate both the tape and the strip lights. If not, then no lights would be installed in this area. Attachment B provides additional information.

It is my understanding that if a trailer manufacturer installs the three identification lights at the top, rear of the trailer, then the clearance lights can be installed at the bottom of the trailer. If the identification lights are mounted at the b ottom of the trailer, then the clearance lights must be at the top, rear. See attachment C.

To provide a better understanding of this technology and the proposed lighting system, I can provide an on-site demonstration for the NHTSA and for George Parker of the Office of Research and Development.

I hope that this information concerning the revised lighting system will provide your office wilh sufficient data to evaluate the system and rule that it is in compliance with the requirements of 49 U.S.C. 30112(a).

Thank you for your time and consideration and I look forward to receiving your letter.

(Attachments A-C omitted.)

ID: nht95-2.58

TYPE: INTERPRETATION-NHTSA

DATE: April 27, 1995

FROM: Musa K. Farmand -- Gonzalez And Farmand, P.A.

TO: Mary Versailles -- NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 5/9/95 LETTER FROM JOHN WOMACK TO MARY VERSAILLES (A43; STD. 208)

TEXT: Dear Ms. Versailles:

Thank you for speaking with me this morning regarding 49 CFR Section 571.208, 4.1.5.2 (c) 2. As you may recall, I am an attorney practicing law in Orange Park, Florida. I represent two plaintiffs who were seriously injured in an automobile wreck in Apr il 1993. Florida has a mandatory seat belt statute which allows evidence of a person's failure to wear the seat belt only in those instances where failure to wear the seat belt caused or contributed to the accident. Florida does not allow a mitigation of damages defense with respect to an alleged failure to wear a seat belt. In our case, we were successful in getting the seat belt defense stricken since there were no facts which would indicate that any alleged failure on the part of the plaintiff to wear a seat belt caused the incident in the first place.

Nonetheless, defense counsel in our case has moved to amend his answer to include as an affirmative defense the argument that 49 CFR 571.208, 4.1.5.2 (c) 2 conflicts with Florida law in that the federal regulation requires that each state allow for a mit igation of damages defense in its seat belt statute. A copy of the defendant's motion and amended affirmative defense is attached for your review.

We contacted the Legal Research Center, a legal research group located in Minnesota, to help research this issue. They contacted your office on April 24, 1995. They spoke with you and Mr. Clark Harper, of the Frontal Crash Protection Division, Office o f Vehicle Safety Standards. According to a letter we received from Legal Research ("LRC") and our telephone discussions with them regarding this issue, they have indicated the following based on their discussions with you and Mr. Harper:

1. The provision that was cited by the defendant does not exist anymore. It has been replaced by air bags standards in 1993 specifically 38 FR 46551 (September 2, 1993). Indeed, our research has revealed that, effective October 1, 1994, Section [Illeg ible Words] (2) no longer existed.

According to LRC, the Section was only a tool that was taken into consideration by the Secretary of Transportation when he was considering the recission of the auto restraint systems, which he never did.

2. Therefore, the whole section is a moot point.

3. Even when the section did exist, it was not intended to be pre-empted.

4. Even if the section did exist, it would not apply to our situation since it has nothing to do with any state "seat belt defenses".

In essence, based on the foregoing, it would appear that the defendant's motion is without merit. Of course, it would be helpful to have a letter or an interpretation from the Office of the General Counsel regarding this particular provision.

As we've discussed, the purpose of this letter is to request an interpretation and/or opinion letter regarding the applicability of 49 CFR 571.208, 4.1.5.2 (c) 2 to this situation. We already appreciate your cooperation in speaking with us and LRC in re gards to this matter. I look forward to hearing from you.

ID: nht95-2.59

TYPE: INTERPRETATION-NHTSA

DATE: April 28, 1995

FROM: R F Tolley -- Senior Development Engineer, New Products Office, Magneti Marelli UK Ltd. Lighting Division

TO: Chief Council -- Office of Vehicle Safety Standards, NHTSA

ATTACHMT: ATTACHED TO 6/8/95 LETTER FROM JOHN WOMACK TO R. F. TOLLEY (A43; STD. 108)

TEXT: Dear Chief Council

Question concerning FMVSS108

External Aiming - Torque/Deflection Test

I would like to raise a question with you concerning the interpretation of the torque/deflection test contained in FMVSS108 section S7.8.5.1.(a).

I understand that this test is to take into account the weight of beam aiming equipment when aiming lamps. However I believe the instructions for performing the test are not sufficiently precise and can be interpreted in different ways.

Please see attached sketch which I have used to explain my query. In order to determine the downward force which is applied to the lamp, so as to cause the lamp aim to rotate downward, it is necessary to define the centre of rotation of the force. Sinc e torque = downward force multiplied by the distance to the centre of rotation of the force, then

downward force = Torque (20lbf.in) / distance to the centre of rotation of the force

My question is, where is the centre of rotation of the force taken to be? Is it?

a) the centre of the aiming pad pattern,

b) the point at which the axis (which passes through the centre of the aiming pad pattern and is perpendicular to the aiming reference plane), passes through the aiming reference plane,

c) the centroid of the reflector,

d) the centre of rotation of the headlamp assumed to be the centre of the pattern formed by the headlamp adjusters,

e) some other point.

With large, angled modern lamps the difference between the above points can be great, therefore it is important to select the correct point.

In summary my question is- When applying a downward force to create a downward torque (with respect to lamp aim), where is the centre of rotation of the force taken to be?

Attachment: FMVSS 108 EXTERNAL AIMING TORQUE DEFLECTION TEST

(Graphics omitted.)

ID: nht95-2.6

TYPE: INTERPRETATION-NHTSA

DATE: March 20, 1995

FROM: Malcolm Bricklin -- President, The Electric Bicycle Company

TO: Ricardo Martinez -- Administrator, NHTSA

TITLE: Re: Petition for Exemption

ATTACHMT: ATTACHED TO 4/8/95 LETTER FROM PHILIP R. RECHT / JOHN WOMACK TO MALCOLM BRICKLIN (A43; PART 555)

TEXT: Dear Mr. Martinez:

The Electric bicycle Company is located at 17351 West Sunset Boulevard, Pacific Palisades, Los Angeles, CA 90272. It was incorporated in the State of Nevada.

This is a petition to be exempted from two Federal Motor Vehicle Safety Standards for electrically assisted bicycles that we intend to manufacture, the "EV Warrior". The basis of the petition is that compliance with the standards, in this instance, will constitute a greater hazard to the general public and will result in more accidents caused by operator error than the alternatives that we propose. The standards for which the exemptions are requested are both set forth in:

Standard No. 123, Motorcycle controls and displays.

As you can tell from the enclosed Product Profile, the EV Warrior is essentially a multi-speed bicycle with an attached electric motor that drives the rear wheel through a friction drive wheel against the rear tire. The transmissions of each power sourc e are completely separate. Whereas the bicycle employs 6 to 21 speed derailleur shifting, the electric assist motor has no gears and no clutch. Without the electric assist motor - which can be easily removed, the device is a fully functioning bicycle an d would fall under the regulations of the Consumer Product Safety Act.

Our target market is minors and young adults whose experience riding two-wheelers derives from bicycles rather than motorcycles. In 1993, 13 million bicycles were sold in the United States compared with 488,000 motorcycles in the same year. To prevent operator error in the motoring environment, controls should be consistent with what bicycle riders have become accustomed. Two MVSS Standards are contrary to bicycle operation: Location of front and rear brake levers and use of a twist grip throttle.

The CPSC requires that the front brake be located on the left handlebar and the rear brake on the right handlebar [16 CFR 1512, Standards for Bicycles, Part 1512.5 Braking System, subsection (b) (8)] However, MVSS Standard 123, S5.2.1 Control location an d operation, requires that "If a motorcycle is equipped with a supplemental rear brake control, the control shall be located on the left handlebar."; and in Table 1., item 10. that the front wheel brake be located on the left handlebar. We believe that this regulatory inconsistency poses a serious threat to the safety of the riders of our bicycles and other road users.

MVSS Standard 123, S5.2.1 Control location and operation, Table 1., item 8. mandates a twist grip throttle on the right handlebar. though there is no CPSC mandate, more than 50% of bicycles sold through independent bicycle dealers in the united states l ast year were equipped with twist grip derailleur shifters on the handlebars. This is one of the fastest growing trends in the bicycle industry as these sales are double the sales volume of the year before. "Grip Shifters" are also sweeping the interna tional market. (For further information, we refer you to OEM Sales, SRAM Corporation/Grip Shift, 361 W. Chestnut, Chicago, IL, 60610, Telephone: 312-664-8800, Facsimile: 312-664-8826).

In addition, we have found that by using a thumb operated potentiometer throttle that self closes to stop upon release, the operator: 1.) more naturally releases the throttle when reaching for the brake; and, 2.) generally tends to rely less upon the electric assist and more on their own effort to power the bicycle.

A denial of our petition would confuse and endanger the very public the MVSS are designed to protect. Granting the exemption would be in the public interest and consistent with the National Traffic Safety and Motor Vehicle Safety Act by allowing the use of controls that are standard to the great majority of prospective users.

We intend to introduce an entire generation to electric vehicles. Most kids are experienced with bicycles. Electric bicycles will allow the smoothest and most natural transition to electric vehicles.

With your cooperation, we will quickly bring to market a vehicle that is safe and effective, and will dramatically reduce air pollution, traffic congestion and depletion of non-renewable fossil fuels all while improving the health of the rider.

Brochure omitted.

ID: nht95-2.60

TYPE: INTERPRETATION-NHTSA

DATE: April 28, 1995

FROM: Thomas L. Wright -- Acting Manager, MVS Customer Services, State Of New Jersey, Department Of Law And Public Safety, Division Of Motor Vehicles

TO: Dorothy Nakama -- Office of Chief Counsel, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 6/27/95 LETTER FROM JOHN WOMACK TO THOMAS L. WRIGHT (A43; PART 567; STD. 1) ALSO ATTACHED TO 7/13/92 LETTER FROM PAUL JACKSON RICE TO JEFFREY PUENTES.

TEXT: Dear Ms. Nakama:

Recently we have had an inquiry from a motorcycle accessory distributor who wants to become a manufacturer of motorcycles. The motorcycles that they intend to manufacture will be assembled with engines from one manufacturer and chassis from another. These engines and chassis have their own certificates of origin. Since New Jersey does not license manufacturers, we have suggested that these vehicles be titled as reconstructs. This company does not want to pursue reconstructed titling as they feel t hat it devalues their product and because of problems incurred with other jurisdictions accepting the title.

We are attempting to gather information on how an enterprise becomes a recognized manufacturer, issue certificates of origin, and assign VIN's. We would appreciate any information you can provide us with concerning these matters.

ID: NCC-220316-001 Aircraft Refueler.Beyer.30102

U.S.Department of Transportation 

National Highway Traffic Safety Administration

Office of the Chief Counsel

1200 New Jersey Avenue SE. 

Washington, DC 20590

October 1, 2025

Lawrence A. Beyer 674 Lake Road

Webster, NY 14580 

Lbeyer l@rochester.rr.com

Dear Mr. Beyer, 

This responds to your March 13, 2022 letter to the National Highway Traffic Safety Administration (NHTSA) inquiring whether a certain aircraft refueling truck would constitute a motor vehicle under the National Traffic and Motor Vehicle Safety Act of 1966 ("Safety Act").1 Based on the specific information provided in your request and supporting documentation, we conclude that this aircraft refueling truck would not be considered a "motor vehicle.". Accordingly, the Safety Act would not prevent its importation into the United States. 

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 only aims to provide clarity regarding existing requirements under the law at the time of signature. 

Background 

The Safety Act authorizes NHTSA to regulate motor vehicle safety by promulgating and enforcing Federal Motor Vehicle Safety Standards (FMVSS) that set performance requirements for new motor vehicles and new items of motor vehicle equipment. The Safety Act defines a "motor vehicle" as "a vehicle driven or drawn by mechanical power and manufactured primarily for use on public streets, roads, and highways."2 The Safety Act prohibits the import of motor vehicles into the United States unless the motor vehicle complies with all applicable FMVSS and bears a permanently affixed label by the vehicle's original manufacturer certifying compliance.3 

According to your letter, in June 1998, Advanced Engineered Products, Limited ("Advanced") manufactured an aircraft refueling truck for Calgary Fuel Facilities Corporation ("Calgary

1 Codified at 49 U.S.C. Chapter 301.
2 49 U.S.C. § 30102(a)(7).
3 See 49 U.S.C. § 30112(a)(l). 

Fuel") for use at the Calgary airport. In your communications with NHTSA, you included a link to the listing of the unit, which indicates several specialized attributes.4 The three-axle vehicle has a 6,500-gallon tank that, when full of fuel, weighs 44,000 pounds. You noted that airport road surfaces have higher weight capacity than public roads, permitting units to transport heavier loads on fewer axles.
Further, you stated that the unit has a muffler system low to the ground below the front bumper. You explained that the aircraft's safety requires a low muffler system because this ensures that the exhaust remains far enough away from the aircraft's refueling connection. You explained that when the unit is full of fuel, the weight compresses the suspension and reduces the distance between the road surface and the exhaust system. This could be dangerous given potential speedbumps, potholes, or other modifications or impairments on public roads that could damage the required exhaust system. Finally, you stated that the unit has a rear warning guard that is wider than the unit. 

Calgary Fuel used the unit at the Calgary airport from June 1998 until September 2015. In September 2015, Eastway Tank Pump & Meter Limited ("Eastway") bought the unit from Calgary Fuel and shipped the unit within Canada from Calgary to Ottawa on a flat deck trailer. In September 2021, Eastway coordinated the transportation of the unit from Canada to a storage yard in New York. According to your subsequent communications with our office, Eastway was unable to contract for a flatbed trailer to transport the unit. Thus, the unit was operated on public roads for a single time during transport to the storage yard. Eastway provided a warning vehicle containing "Slow Vehicle" signage that followed the unit during transit. 

In October 2021, Eastway attempted to import the unit into the United States. The import process requires submission of a completed Form HS-7.5 Box 2A on the form was checked as the basis for import.6 Officers from U.S. Customs and Border Protection (CBP) contacted NHTSA to determine whether the vehicle could be lawfully imported into the United States under the statutes and regulations administered by NHTSA under Box 2A. NHTSA responded by stating that the vehicle did not have a certification label permanently affixed by the vehicle's original manufacturer and did not have a correct Vehicle Identification Number

4 htt,ps://usedoilandfiretrucks.com/products/1998-intemational-refueler/
5 Declaration: Importation of Motor Vehicles and Motor Vehicle Equipment Subject to Federal Motor Vehicle Safety, Bumper and Theft Prevention Standards, Nat'l Highway Traffic Safety Admin., https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/hs7 rv9-tag.pdf.
6 Box 2A provides:

The vehicle or equipment item conforms to all applicable Federal Motor Vehicle Safety Standards (or the vehicle does not conform solely because readily attachable equipment items that will be attached to it before it is offered for sale to the first purchaser for purposes other than resale are not attached), and Bumper and Theft Prevention Standards, and bears a certification label or tag to that effect permanently affixed by the original manufacturer to the vehicle or affixed by the manufacturer to the equipment item or to its delivery container in accordance with applicable National Highway Traffic Safety Administration. 

(VIN) as required by Box 2A. For these reasons, NHTSA stated that the unit was ineligible for importation under Box 2A and CBP seized the unit.7 

Discussion 

In your letter, you asked whether the aircraft refueling truck you reference is a "motor vehicle" under the Safety Act. We conclude that the vehicle you describe is not a "motor vehicle." In so opining, we distinguish this from our 1972 interpretation letter opining that an airport refueling vehicle is a "motor vehicle."8 NHTSA has previously held that airport runway vehicles, such as airport baggage conveyors, do not meet the definition of a "motor vehicle" and are not subject to FMVSS, even if they are operationally capable of highway travel.9 However, in a 1972 interpretation, NHTSA stated that an airport refueling vehicle would be a motor vehicle because it "may frequently be driven on public roads such as perimeter roads between oil tanks and the airport."10  

The features of the vehicle you describe are substantially different from the features discussed in the 1972 letter. To inform our conclusion about whether your vehicle is a "motor vehicle," we turn to evaluating the design and actual use of the unit at issue. 

More recent interpretation letters analyze the question of whether such a vehicle is considered a "motor vehicle" using a five-factor test.11 We discuss these factors in turn.

1. Whether the vehicle is advertised for use on-road and off-road, or whether it is advertised exclusively for off-road use. 

While Advanced, the original equipment manufacturer for the purposes of this response, has gone out of business, NHTSA examined the advertising of similar businesses that manufacture aircraft refuelers.12 This sample suggests aircraft refuellers are intended exclusively for off­ road use on airport roads to refuel aircraft, contrary to the description described in the 1972 interpretation. Your letter supports this inference, noting that the unit in question was used exclusively at the Calgary airport from June 1998 until September 2015. This factor supports 

7 If you can substantiate that the vehicle was manufactured in 1998, it may be imported today even if it was a "motor vehicle" under the Safety Act. The prohibition against importing motor vehicles not certified to meet the applicable FMVSSs at the time of manufacture does not apply to vehicles that are 25 years or older. These vehicles can be imported under Box 1 of Form HS-7. Nevertheless, we will opine on the issue of whether this vehicle is a motor vehicle to remove any ambiguity about whether the vehicle could have legally been imported in 2021.
8 Letter to Garsite Prods., Inc., Apr. 17, 1972, https://www.nhtsa.gov/internretations/nht72-52.
9 Letter to Irving Gingold, June 30, 1988, https://www.nhtsa.gov/internretations/2864o; Letter to Mac Yousry, June 10, 2015, https://www.nhtsa.gov/internretations/30102-what-motor-vehicle-mac-yousry-14-000891-5114.
10 Letter to Garsite Prods., Inc., Apr. 17, 1972, https://www.nhtsa.gov/internretations/nht72-52.
11 E.g., Letter to M. James Lester, NaturalForm, Inc., June 26, 2001, https://www.nhtsa.gov/internretations/motorvehicledefinition.
12 Aircraft Refuelers, Advance Engineered Prods., https://advanceengineeredproducts.com/products/aircraft­
refuelers/, Aircraft Refueller Company, https://arc-refuellers.be/, Refuel International, https://refuelin.com/. 

the finding that this aircraft refueler is not a "motor vehicle" as that term is defined in the Safety Act.

2. Whether the vehicle's manufacturer or dealers assist the vehicle's purchasers in obtaining certificates of origin or title documents to register the vehicle for on­ road use. 

We have no evidence to inform whether Advanced assisted Calgary Fuel, the vehicle purchaser, in documentation necessary to register the vehicle for on-road use. You state that the vehicle does not have a vehicle identification number (VIN). Without a VIN, we believe it would be difficult for the vehicle to be registered in any U.S. State. Further, the unit lacked a certification label permanently affixed by the vehicle's original manufacturer. This suggests that Advanced did not designate or register the vehicle for on-road use and weighs against considering this vehicle to be a "motor vehicle."  

3. Whether the vehicles are sold by dealers also selling vehicles that are classified as motor vehicles.

The manufacturer of the vehicle you ask about has gone out of business. Therefore, we are unable to evaluate this factor. 

4. Whether the vehicle has affixed to it a warning label stating that the vehicle is not intended for use on the public roads. 

Your letter indicates that the aircraft refueler has a low muffler system that makes it unsuitable for on-road use when it is loaded with fuel because it will not have sufficient ground clearance to navigate ordinary obstacles on public roads. Your letter further indicates that the refueler was transported several times within Canada towed on a flat deck trailer, rather than as a self­
operating unit on public roads. When the unit did travel on public roads for a single time due to an inability to arrange transport, during that trip, Eastway provided a warning vehicle that followed the unit containing "Slow Vehicle" signage. The unit in question has a rear warning guard that is wider than the unit itself. While it is unclear whether the "Slow Vehicle" signage or the rear warning guard explicitly included warning label text, the presence of the signage and guard, and the typical use of the vehicle, suggest that the unit is not intended for use on public roads. 

5. Whether states or foreign countries have permitted or are likely to permit the vehicle to be registered for on-road use. 

The lack of a vehicle identification number, permanently affixed certification label, the use of a flat-bed trailer for primary transportation, and the use of warning signage when operated on public roads for a single time, suggests that the unit is not independently suitable for public roads. These factors make it unlikely to be registered as a motor vehicle in any U.S. State, and the lack of a vehicle identification number would make it unlikely such a vehicle would be registered for on-road use in Canada. There is no evidence that this vehicle was registered in Canada. This factor suggests that the unit would not be considered a motor vehicle. 

Conclusion 

Based on the considerations in NHTSA's five-factor test and the description of the unit you provided, the aircraft refueler in question would not be considered a "motor vehicle" under the Safety Act. It is similar to airport runway vehicles discussed in prior NHTSA interpretations in that, while perhaps operationally capable of traveling on public roads, it was manufactured and sold primarily for off-road use. Furthermore, it is distinguishable from the aircraft refueling vehicle that NHTSA considered in its 1972 interpretation. 

I hope this information is helpful. If you have any further questions, please feel free to contact David Jasinski of my staff at interpretations.NHTSA@dot.gov.

Sincerely,

Peter Simshauser 

Chief Counsel

Dated: 10/1/25
Ref: Section 30102

ID: NCC-250121-001 FMVSS No 135.Parking Brake Indicator-lanetta signed 11.8.25

October 8, 2025

U.S. Department of Transportation 

National Highway Traffic Safety Administration 

Office of the Chief Counsel 

1200 New Jersey Avenue SE. 

Washington, DC 20590

Ms. Christie Iannetta 

Nelson Mullins 

101 Constitution Avenue, NW 

Suite 900

Washington, DC 20001   

Dear Ms. Iannetta:

I am writing in response to your letter addressed to NHTSA dated January 15, 2025, asking the agency to reconsider an interpretation issued on October 31, 2024 ("the interpretation").1 The interpretation was issued in response to a request you submitted on behalf of an anonymous client on February 26, 2024. In the request, you asked for clarification on Federal Motor Vehicle Safety Standard (FMVSS) No. 135, "Light vehicle brake systems." Specifically, you asked about paragraph S5.5.1, which sets out requirements for when certain brake indicators must be activated. In the interpretation, the agency concluded that the parking brake system described in your letter likely would not comply with FMVSS No. 135's requirements. 

Your January 15 letter requests that we reconsider the interpretation. After considering your request and evaluating the conclusion and analysis in the interpretation, we do not believe we misunderstood your original interpretation request, and we are not reconsidering the interpretation. A detailed explanation of our reasoning follows. 

Background 

By way of background, 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. The following represents our opinion based on the facts provided in your letter. 

Please also note that our answer below is based on our understanding of the specific information provided in your letter. This 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 

1 NHTSA Interpretation File Search, ID: NCC-230308-001, https://www.nhtsa.gov/interpretations/ncc-230308-001- nelsonmullinsparkingbrakeindicatorinterp.

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 establishes requirements for light vehicle braking systems. Paragraph S5.5.1 therein 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." Therefore, if the parking brake is applied and the vehicle's ignition is in the "on" position, a parking brake indicator must be activated. 

You explain that your client's vehicle uses an Electronic Parking Brake (EPB) system where the parking brake can be applied manually by the driver or automatically by the system. The driver can engage the parking brake via the in-vehicle control at any time before shifting the vehicle into park, and when the parking brake is engaged by the driver, the parking brake indicator displays clearly in front of the driver. However, the EPB system can also apply the parking brake on its own, and it does so whenever the vehicle is shifted into park. If the EPB system engages the parking brake on its own, the parking brake indicator does not display. Finally, regardless of how the parking brake is engaged (by the driver or by the EPB system), the parking brake always disengages automatically once the vehicle is shifted out of park, or in some vehicles, when the brake pedal is depressed. 

In the interpretation we concluded that your client's system is likely not compliant with the requirements of FMVSS No. 135. Specifically, we explained that S5.5.l(c) requires that if a vehicle ignition is in the "on" position and the parking brake is applied, an indicator must activate to inform the driver of the status of the parking brake. You may reference the interpretation for our complete analysis on the issue. 

In your January 15 letter, you express your belief that we misunderstood an important fact about the manufacturer's parking brake system, and that we failed to consider relevant regulatory context. 

NHTSA's Response 

We adequately understood the functionality of your client's parking brake system, and we also considered all of the relevant regulatory background. 

NHTSA Did Not Misunderstand Your Client's EPB System 

You indicate that we purportedly failed to understand that it is impossible for your client's vehicle to be driven with the parking brake applied because the system is designed to disengage whenever the vehicle is shifted out of park. Your letter quotes the following line from the interpretation as evidence that we misunderstood this crucial fact about the EPB system: "nothing prevents the vehicle from driving during this engagement." (See interpretation p. 3, ID: NCC-230308-001). 

When we drafted the interpretation, we did so with a complete understanding that your client's vehicle is designed to make it impossible to drive with the parking brake activated. We considered this fact when analyzing your client's system under the requirements of paragraph S5.5.1(c). We concluded that even though your client's vehicle design may potentially address the safety concern of driving with the parking brake activated, manufacturers may not disregard FMVSS requirements because they feel they have resolved the safety issue the standard was designed to address. As we stated in the interpretation, "[I]f 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." Until the standard is amended, manufacturers must certify in good faith to the current requirements. 

NHTSA Did Not Ignore Important Regulatory Context 

You assert that the stated purpose of paragraph S5.5.l(c) is to prevent drivers from driving with the parking brake on, and your client's EPB system addresses that safety concern. Not only did we consider this argument in the interpretation, but our response to this argument was a central component of the interpretation. As we stated in the interpretation:

Just because a manufacturer has designed a system that purports to resolve, through 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. 

We understood then that your client believes it has created an EPB system that addresses the stated safety purpose of paragraph S5.5.l(c)'s parking indicator requirement. As noted, manufacturers must certify compliance with the express terms of an FMVSS, and not just with its stated purpose. In this case, we believe that even if your client's system may address the stated safety purpose underlying paragraph S5.5.l(c), it does not comply with the paragraph's requirements. 

Nor is your argument about the test procedures set out in FMVSS No. 135 S7.12.2 persuasive. You note that the parking brake test procedure requires a vehicle to be put into neutral and the parking brake applied, after which the parking brake must hold the vehicle stationary for a specific amount of time. One of the steps in the test procedure (S7.12.2(m)) is for the test conductor to verify the operation of the parking brake application indicator. You assert that the parking brake indicator is only evaluated after the performance of the steps within the test procedure in S7.12.2, during which the parking brake is applied manually. 

However, nothing in the parking brake test procedure negates paragraph S5.5.l(c)'s parking brake indicator requirement. The requirements that the brake system warning indicators illuminate under specified conditions exists independent of any test procedure. The duration during which a brake system warning indicator must be displayed is addressed in paragraph S5.5.3, which provides that each warning indicator "shall remain activated as long as the condition exists, whenever the ignition ('start') switch is in the 'on' ('run') position, whether or not the engine is running." Nothing in the test procedures purports to alter or limit this requirement. Thus, your client must be able to certify in good faith that its vehicle's parking brake indicator appears in plain view of the driver whenever the parking brake is engaged. We do not believe your client is able to do so based on your description of its EPB system. We note also that the final inspection procedure in paragraph S7.17 requires inspection of "[t]he brake system indicators, for compliance with operation in various key positions, lens color, labeling, and location, in accordance with S5.5." We expect that noncompliance with the requirement of paragraph S5.5.l(c) would be observed during this final inspection. 

I hope this letter provides clarity on NHTSA's stance on this matter. If you have any further questions, please contact Mr. David Jasinski of my staff at interpretations.NHTSA@dot.gov.

Sincerely,

Peter Simshauser 

Chief Counsel

Dated: 10/8/25
Ref: FMVSS No. 135