ID: nht95-7.32

TYPE: INTERPRETATION-NHTSA

DATE: October 26, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Hugh J. Bode, Esq. -- Reminger & Reminger

TITLE: NONE

ATTACHMT: ATTACHED TO 8/21/95 LETTER FROM HUGH J. BODE TO JOHN WOMACK

TEXT: Dear Mr. Bode:

This responds to your letter concerning whether 49 U.S.C. @@ 30101 et seq. (formerly the National Traffic and Motor Vehicle Safety Act) requires a motor vehicle manufacturer to ensure that its vehicle continues to comply with applicable Federal motor vehicle safety standards (FMVSSs) after the first retail purchase of the vehicle.

You specifically ask about FMVSS No. 124, "Accelerator Control Systems," and its application to a 1988 Dodge Ram 50 pickup truck. It appears from the questions you ask that corrosion developed inside the carburetor of the pickup truck at some point during the life of the vehicle, such that the carburetor would not return to idle in accordance with the requirements of Standard No. 124.

You asked us to "confirm the accuracy" of a number of statements. Your first statement, concerning the application of the FMVSSs generally, is as follows:

As we understand it, former @ 108(a) (1) (A) of the National Traffic and Motor Vehicle Safety Act, 49 U.S.C. @ 30112(a), prohibits any person from manufacturing, selling or introducing into commerce any new motor vehicle unless the vehicle is in conformity with all applicable FMVSS. However, the Safety Act further provides that the requirement that a vehicle comply with all applicable FMVSS does not apply after the first purchase for purposes other than resale, i.e., the first retail sale of the vehicle. Safety Act former @ 108 (b) (1), 49 U.S.C. @ 30112 (b) (1). After the first retail sale, the only provision in the Safety Act that affects a vehicle's continuing compliance with an applicable FMVSS is set forth in former @ 108(a) (2) (A), 49 U.S.C. @ 30122(b), which prohibits certain persons from knowingly rendering inoperative a device installed in a motor vehicle in compliance with an applicable FMVSS.

Your general understanding is correct. However, a manufacturer has responsibilities in addition to those in @ 30112, that may bear upon on "continuing compliance" of its vehicle. Under @@ 30118-30122 of our statute, each motor vehicle manufacturer must ensure that its vehicles are free of safety-related defects. If NHTSA or the manufacturer of a vehicle determines that the vehicle contains a safety-related defect, the manufacturer must notify purchasers of the defective vehicle and remedy the problem free of charge.

This is not to say that the development of the corrosion in the carburetor necessarily constitutes a safety-related defect. Rather, we acknowledge the possibility of such a finding in certain circumstances, such as where the corrosion developed unreasonably quickly in the vehicle and the problem was such that it could lead to crashes involving injuries or fatalities.

State law could also be relevant to this issue. For example, as part of its vehicle inspection requirements, a State could require that the accelerator control systems on vehicles "continue to comply" with the requirements of Standard No. 124.

With the above discussion in mind, I will now address your other four questions on Standard No. 124.

Question 1. We ask that NHTSA confirm that FMVSS 124 is a standard that a given vehicle must comply with only at the time of the first retail sale of the vehicle.

As explained in our answer above, your understanding is correct with regard to our requirements (49 U.S.C. @ 30112). There may be State requirements that apply.

Question 2. We ask NHTSA to confirm that if a carburetor installed in a 1988 Dodge Ram 50 pickup truck met all the requirements of FMVSS 124 at the time of the truck's first retail sale, but, after the sale, due to in-service conditions, corrosion developed inside the carburetor so the carburetor would not return to idle in accordance with the requirements of S5.1, S5.2, and S5.3 of FMVSS 124, that circumstance would not render the vehicle in violation of FMVSS 124.

Your understanding is essentially correct. As permitted by Federal law, Chrysler sold the truck based upon its own certification of compliance with FMVSS No. 124. That corrosion developed in the system may or may not be relevant with respect to the existence of a safety-related defect.

Question 3. We ask NHTSA to confirm that all of the performance standards imposed by FMVSS 124 are contained in S5.1, S5.2 and S5.3 of FMVSS 124 and that S2 headed PURPOSE does not impose any separate regulatory obligation beyond those contained in S5.

While your understanding is essentially correct, note that Standard No. 124 and other motor vehicle safety standards are minimum performance standards.

Question 4. We ask you to confirm that the performance standard set forth in FMVSS 124 does not contain any requirement relating to durability or corrosion resistance.

Standard No. 124 does not specify a test for corrosion resistance. It is unclear what you mean by "durability." The requirements of the standard must be met when the engine "is running under any load condition, and at any ambient temperature between - 40 degrees F. and + 125 degrees F. . ." (S5) In addition to the performance regulated by Standard No. 124, each manufacturer must ensure that its motor vehicle does not have a safety-related defect.

If you have any questions about the information provided above, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992.

ID: nht95-7.33

TYPE: INTERPRETATION-NHTSA

DATE: October 30, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Larry W. Strawhorn -- Vice President of Engineering, American Trucking Associations

TITLE: NONE

ATTACHMT: ATTACHED TO 9/6/95 LETTER FROM LARRY W. STRAWHORN AND EARL EISNHART TO JOHN G. WOMACK

TEXT: Dear Mr. Strawhorn:

This letter responds to your request for an interpretation of the antilock malfunction indicator requirements set forth at S5.2.3.3 of Standard No. 121, Air Brake Systems. This provision explains the situations in which the trailer lamp malfunction indicator must remain activated. Section S5.2.3.3 reads as follows:

S5.2.3.3 Antilock Malfunction Indicator. Each trailer (including a trailer converter dolly) manufactured on or after March 1, 1998 and before March 1, 2006 shall be equipped with a lamp indicating a malfunction of a trailer's antilock brake system. Such a lamp shall remain activated as long as the malfunction exists whenever the power is supplied to the antilock brake system. The display shall be visible within the driver's forward field of view through the rearview mirror(s), and shall be visible once the malfunction is present and power is provided to the system. (Emphasis added.).

In particular, you request that the agency confirm your belief that the lamp activation pattern for trailers may be such that the bulb be ON when the antilock system is working properly and OFF when a malfunction exists, the antilock system is not getting electrical power, or the lamp bulb is burnt out. You contended that such an activation pattern provides a fail safe pattern i.e., it will signal an inoperative antilock system even when the system is not receiving electrical power or the lamp bulb is burnt out.

NHTSA disagrees with your suggested reading of the malfunction indicator requirements. Such a reading would be inconsistent with S5.2.3.3's language stating that the lamp must "remain activated as long as the malfunction exists whenever the power is supplied to the antilock brake system." As with other malfunction indicators, the agency intends the malfunction indicator to activate when a malfunction exists and not activate when the system is functioning properly. To require otherwise would be inconsistent with our requirements for other indicators and thus would create confusion. Please note that NHTSA provided a lengthy discussion about the issue of a malfunction indicator's activation protocol in the March 10, 1995 final rule. (60 FR 13216, 13246) The agency stated that in response to an ABS malfunction, a trailer or tractor indicator must activate and provide a continuous yellow signal. The agency explained that such a common indicator pattern standardizes the activation format, thus reducing ambiguity and confusion and expediting Federal and State inspections.

I hope this information has been helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992.

ID: nht95-7.34

TYPE: INTERPRETATION-NHTSA

DATE: November 7, 1995

FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA

TO: James J. Gregorio

TITLE: NONE

ATTACHMT: Attached to 9.23.95 letter from James J. Gregorio to John Womack

TEXT: Dear Mr. Gregorio:

This responds to your letter of September 23, 1995, requesting" authorization to modify the car seat in my 1992 Plymouth Acclaim." Your letter states:

Presently, my car is equipped with hand controls which alleviates a condition of chronic tendinitis in my right ankle. Unfortunately, there is practically no room between the hand controls and my knees. My knees constantly bang up against the hand controls. The resulting consequence is that I now have tendinitis in both knees. Modifying the car seat will allow me to push the car seat back far enough to give space to my injured knees.

You enclosed a letter from your physician stating that recovery could take several years.

In summary, our answer is that you may have your vehicle modified. NHTSA will not institute enforcement proceedings against a repair business that modifies the seat on your vehicle to accomodate your condition. A more detailed answer to your letter is provided below.

I would like to begin by noting that repair businesses are permitted to modify vehicles without obtaining permission from NHTSA to do so, but are subject to certain regulatory limits on the type of modifications they may make. In certain limited situations, we have exercised our discretion in enforcing our requirements to provide some allowances to a repair business which cannot conform to our requirements when making modifications to accommodate the special needs of persons with disabilities. Since your situation is among those given special consideration by NHTSA, this letter should provide you with the relief you seek.

Our agency is authorized to issue Federal Motor Vehicle Safety Standards (FMVSS) that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are required to certify that their products conform to our safety standards before they can be offered for sale. Manufacturers, distributors, dealers, and repair businesses are prohibited from "knowingly making inoperative" any device or element of design installed on or in a motor vehicle in compliance with an applicable FMVSS. Violations of this prohibition are punishable by civil fines up to $ 1,000 per violation.

Moving a seat, and presumably moving the seat belts for the seat, could affect compliance with four safety standards: Standard No. 207, Seating Systems, Standart No. 208, Occupant Crash Protection, Standard No. 209, Seat Belt Assemblies, and Standard No. 210, Seat Belt Assembly Anchorages. Your letter does not provide any information regarding why the modification to your seat cannot be done in a way that would not violate the make inoperative prohibition.

However, in situations such as your where a vehicle must be modified to accommodate the needs of a particular disability, we have been willing to consider any violations of the "make inoperative" prohibition a purely technical one justified by public need. As I have already noted above, NHTSA will not institute enforcement proceedings against a repair business that modifies the seat on your vehicle to accommodate your condition.

We caution, however, that only necessary modifications should be made to the seat, and the person making the modifications should consider the possible safety consequences of the modifications. For example, in moving a seat, it is critical that the modifier ensure that the seat is solidly anchored in its new location. You should also be aware that an occupant of a seat which has been moved rearward may have less protection in a crash if the seat is too far rearward relative to the anchorages of the safety belts for that seat. Finally, if you sell your vehicle, we encourage you to advise the purchaser of the modifications.

I hope this information has been helpful. If you have any other questions or need some additional information in this area, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

ID: nht95-7.35

TYPE: INTERPRETATION-NHTSA

DATE: November 8, 1995

FROM: Jane Thornton Mastrucci -- Thornton, Mastrucci and Sinclair

TO: John Womack -- Chief Counsel, NHTSA

TITLE: NONE

ATTACHMT: 12/26/95 letter from Samuel J. Dubbin (signed by John Womack) to Jane Thornton Mastrucci (A43; Part 571.3; VSA 102)

TEXT: We represent the Dade County School Board with respect to its vehicular litigation.

The Florida Legislature has just passed a new law, F.S. 234.02 (1)(a) which allows a School Board to use, in addition to passenger cars not exceeding eight students, any other motor vehicle designed to transport ten on fewer persons which meets all federal motor vehicle safety standards for passenger cars. Similarly, the Department of Education Rule 6A-3.017 (10)(c) allows the transportation of students, when necessary or practical, in multipurpose vehicles, providing the MPV meets all of the applicable passenger car federal motor vehicle safety standards, except the standard pertaining to window tinting. Copies of both of these statutes are attached.

Would you please advise which passenger vehicles which multipurpose vehicles meet all federal motor safety standards.

Thanking you for your courtesy and cooperation in advance, I remain,

Florida statutes are omitted.

ID: nht95-7.36

TYPE: INTERPRETATION-NHTSA

DATE: November 13, 1995

FROM: David T. Zelis -- Marketing Manager, Buyers Products Company

TO: Office Of Chief Counsel -- NHTSA

TITLE: NONE

ATTACHMT: 12/22/95 letter from Samuel J. Dubbin to David T. Zelis (A43; Part 581)

TEXT: Enclosed please find a copy of literature describing a new product from our company. The Pintle Mount Bumper basically is designed to take the place of a vehicle bumper and the receiver tube assembly on a light duty truck.

Would you please send a copy of NHTSA standards that may apply to the use or manufacture of this product. Please feel free to contact me with any questions, at (216) 974-8888.

Thank you for your assistance.

(Literature omitted.)

ID: nht95-7.37

TYPE: INTERPRETATION-NHTSA

DATE: November 14, 1995

FROM: Terence J. Kann

TO: Ricardo Martinez -- Administrator, NHTSA

TITLE: NONE

ATTACHMT: 12/22/95 letter from Samuel J. Dubbin to Terence J. Kann (A43; Std. 108)

TEXT: I am writing to you concerning Standard No. 108, which amended 49 CFR Part 571 to require application of retro-reflective sheeting or reflex reflectors to provide for greater conspicuity of the sides and rear of trailers. I have the following question. Section S3, Application (a) provides that the standard applies to ". . . trailers (except pole trailers) . . .". Section S5.7 provides that "each trailer of 80 or more inches overall width and with GVWR over 10,000 pounds manufactured on or after 12/1/93, except a trailer designed exclusively for living or office use, shall be equipped with either retro-reflective sheeting . . . reflex reflectors . . . or a combination . . .".

My question is, are pole trailers such as those used in the logging industry, required to have retro-reflective sheeting, reflex reflectors, or a combination? If not, did the NHTSA issue any explanation for failing to extend the requirements to pole trailers? If yes, could you please provide a copy?

Thank you for your assistance. Please don't hesitate to call or write if you have any questions or comments regarding the above.

ID: nht95-7.38

TYPE: INTERPRETATION-NHTSA

DATE: November 15, 1995

FROM: Richard L. Russell

TO: Blane Laubis -- Office of Vehicle Safety Compliance, US Dept. of Transportation

TITLE: NONE

ATTACHMT: 12/22/95 letter from Samuel J. Dubbin to Richard L. Russell (A43; Std. 108)

TEXT: I now have two DOT Approved headlights on my 1956 Jeep and I would like to add two additional Auxiliary Lights to supplement my highbeams. These lights would be wired into the highbeam switch, so that, they can only be used on highbeam and mounted on my bumper below my DOT Approved headlights (36.5" from the ground).

My question is . . . are my auxiliary lights required to be DOT approved? Are they required to be SAE approved? And is there any limitation to bulb wattage for auxiliary lights used to supplement the DOT approved headlights while they are on highbeam?

I understand that the State of California may have regulations to further define or restrict the use of auxiliary lights. I would appreciate your response to these questions at your earliest convenience.

ID: nht95-7.39

TYPE: INTERPRETATION-NHTSA

DATE: November 16, 1995

FROM: Kenneth W. Easterling -- Plan B Engineering, Inc.

TO: Taylor Vinson -- NHTSA; Samuel J. Dubbin -- Chief Counsel, NHTSA

TITLE: Collision Avoidance Technology

ATTACHMT: 12/22/95 letter from Samuel J. Dubbin to Kenneth Easterling (A43; Std. 108); 7/30/93 letter from John Womack to Wayne Ferguson

TEXT: THANK YOU FOR TAKING TIME TO DISCUSS THE DEVELOPMENTS MADE RECENTLY OUR COLLISION AVOIDANCE DEVICE NOW IN THE FINAL DESIGN STAGES. AS PER YOUR DIRECTIVE. I HAVE ATTACHED A BRIEF SYNOPSIS OF THE SUBJECT DEVICE FOR YOUR CONSIDERATION AND OPINION.

IF I CAN PROVIDE ANYTHING FURTHER IN TERMS OF PRODUCT ILLUSTRATION OR EXPLANATION, PLEASE GIVE ME A CALL.

WE SINCERELY THANK YOU IN ADVANCE FOR YOUR PERSONAL COMMENTARY AND SUBMISSION TO MR. DUBBIN'S OFFICE FOR INSPECTION.

VERY BEST REGARDS, KENNETH W. EASTERLING

Attachment

Mr. Samuel J. Dubbin Chief Counsel NHTSA, Room 5219

Subject: Rear End Collision Avoidance Re: Proportional Deceleration Indicator Lamps (aka) G-Lamps

Dear Mr. Dubbin:

In recognition of the significant work and contributions to highway safety, I submit for your consideration and opinion, the concept and justification for G-Lamps.

To be specific, an inertial driven, proportional deceleration indicator lamp as an intended enhancement to existing single filament, on/off style incandescent brake lamps. We have recently entered final design stages on the device and initial tests have revealed some startling results in decreased driver reaction times when compared to the industry standard products.

Building on my work experience within the California Highway Patrol, I recognized the need for motorists to be aware of not only when a vehicle ahead of you was braking, but to what degree the deceleration was be made. Tests have shown reaction times were cut in half when a motorist was visually appraised of increasing, hard braking activity instead of having to judge the rate of diminishing distance between his/her vehicle and the braking motorist (as is the case with on/off style brake lamps). In the case of freeway speeds, these reaction times and distances are accumulated from one vehicle to the next (rear) until ultimately (at freeway speeds) a rear end collision is imminent.

G-Lamps was developed to provide motorists to the rear, visual reference to the degree of braking activity on a real-time basis. Valuable distance is directly proportionate to time lost in reacting to sudden stops or increasingly harder braking. As we all know, there exists a tendency to "ride" our brakes when anticipating slow-downs or stops. This has effectively eliminated the benefits of standard brake lamps. From the time of activation, the degree of braking activity is anyone's guess. To motorists to the rear it may very well end up in excessive vehicle damage and injury liabilities.

For your inspection, explanation of the device is delivered on the following pages. I have tried to be as informative as possible without laboring you with manufacturing details that would rival a sales pitch.

I thank you in advance for your input and contributions to this effort.

Kenneth Easterling, President, Plan B Engineering Inc.

Intent and Purpose

The device was conceived to counter the hazards of hard braking while in traffic at highway speeds. It is intended to enhance existing brake indicator lamp systems and not to deviate from customary and expected visual queues during motor vehicle operation with one important exception.

Specifically, braking activity in excess of normal deceleration (defined as an appreciable decay of forward momentum of the vehicle) would activate decelerometer circuitry housed within the lamp bulb itself and be viewed from the rear as proportionately faster flashing light equating to the degree of deceleration. Normal braking would display customary visual queues as a steady burn of the brake lamp.

It is well established through independent studies and government testing, driver reaction times are severely compromised as the distance between vehicles decrease under various breaking conditions. This scenario is aggravated by the need to visually judge the rate of deceleration of the stopping vehicle and a following driver to respond accordingly.

The device proposed will deliver visual feed-back to following motorists of greater than normal braking activity. The ergonomics of the device are geared to normal reflex actions of potential and proportion. The greater the rate of deceleration of the vehicle the faster the cycles per second of the inertial lamp. Therefore, the following vehicle's response will be to react with potentially greater braking activity much sooner than normal. Thus capturing valuable stopping distance that would otherwise be lost. This problem is further exaggerated by less than desirable visual acuity present in more than three quarters of the motoring public.

Abstract of Device (i.e. form, fit and function) While the form and fit of the device mimic the present day designs for incandescent, filament style lamps, the similarity must end there. Unlike it's predecessor, the inertia lamp is mechanically dynamic in function. To operate the device must be subjected to substantial negative G-forces which can only be generated by the sudden and rapid deceleration the vehicle in which it is mounted. Without these influences, the bulb assembly acts as any other lamp bulb, in terms of constant steady burn associated with normal deceleration rate, when the brake system is activated.

By nature of design, the inertia bulb will activate in concert with the steady burning "normal" brake lamp. Once energized, the inertia flash filament portion of the lamp will increase the flash rate by cycles per second (Hz) proportionate to the rate of declaration. This is a desired means of attaining a quantification of braking magnitude.

Microelectronics technology allows the timing circuitry to be housed within a standard "bayonet" style socket with no modification to the manufacturer's electrical or molded lens structures. State of the art manufacturing techniques allow the device to be fabricated in cost ranges considered to be competitive with existing high performance lamps. The solid state design and minimal parts involved insure long life and serviceability.

Summary

In conclusion, our studies indicate this device to be the most straight forward, technically viable and ergonomically effective means of reducing the single most prolific cause of vehicular collisions today, "the rear-ender". Billions of dollars annually are paid out by insurance companies for damages and bodily injury claims directly related to these types of collisions. Considering the enormous loss in work time, productivity in the economy and personal pain and suffering, the numbers are staggering.

Recently a precedence was set by General Motors with the introduction of the Daytime Running Lamp. Recognizing a simple but highly effective means of vehicular illumination, a major, profit oriented corporation was willing to make a billion dollar investment to highway safety. The motoring public as well as the companies that insure their financial responsibility, have come to expect a product that is as safe as technically and morally possible.

ID: nht95-7.4

TYPE: INTERPRETATION-NHTSA

DATE: September 26, 1995

FROM: Carol Stroebel -- Director of Intergovernmental Affairs, NHTSA

TO: The Honorable Bart Stupak -- U.S. House of Representatives

TITLE: NONE

ATTACHMT: ATTACHED TO 8/21/95 LETTER FROM BART STUPAK TO BRENDA BROWN

TEXT: Dear Mr. Stupak:

Thank you for your letter enclosing correspondence from your constituent, Mr. Kurt B. Ries, concerning our requirements for school vehicles. Your letter was referred to the National Highway Traffic Safety Administration (NHTSA) for reply, since NHTSA regulates the manufacture of all vehicles, including vans and school buses.

Mr. Ries, Director of the Northeast Michigan Consortium, asks for relief from what he believes is a new Federal regulation. The Northeast Michigan Consortium uses a number of 15-passenger vans to transport students to employment training programs and jobs. Mr. Ries believes the new Federal regulation will require all vehicles transporting students, including vans, to be replaced with "mini-school buses," which he believes is economically unfeasible.

I appreciate this opportunity to address your constituent's concerns. As explained below, the new regulation that Mr. Ries is concerned about is not a Federal regulation, but one that Michigan is considering adopting as State law.

NHTSA has issued safety standards applicable to new motor vehicles, including school buses. Under our regulations, a "school bus" is a vehicle carrying 11 or more persons, that is sold to transport children to school or school-related events. Congress has directed NHTSA to require school bus manufacturers to meet safety standards on aspects of school bus safety, including floor strength, seating systems, and crashworthiness. Each seller of a new school bus must ensure that the vehicle is certified as meeting these safety standards.

While NHTSA regulates the manufacture and sale of new school buses, this agency does not regulate the use of vehicles. Thus, we do not have a present or pending requirement that would require Mr. Ries to cease using his vans for school transportation.

The requirements for the use of school buses and other vehicles are matters for each State to decide. We understand from Mr. Roger Lynas, the State Pupil Transportation Director in Michigan, that Michigan is considering changing its school bus definition to make it more similar to NHTSA's. Such an amendment could affect what vehicles can be used for school transportation under State law. For more information about Michigan's proposed amendment, we suggest Mr. Ries contact Mr. Lynas at (517) 373-4013.

NHTSA does not require States to permit only the use of "school buses" when buses are used for school transportation. However, we support State decisions to do so. NHTSA provides recommendations for the States on various operational aspects of school bus and pupil transportation safety programs, in the form of Highway Safety Program Guideline No. 17, "Pupil Transportation Safety," copy enclosed. Since school buses have special safety features that conventional buses do not have, such as padded, high-backed seats, protected fuel tanks, and warning lights and stop arms, they are the safest means to transport school children. Guideline 17 recommends that all buses regularly used for student transportation meet our school bus safety standards.

I hope this information is helpful. If you have any further questions, please do not hesitate to contact me.

ID: nht95-7.40

TYPE: INTERPRETATION-NHTSA

DATE: November 17, 1995

FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA

TO: Jim Young -- Wheeled Coach

TITLE: NONE

ATTACHMT: ATTACHED TO 10/17/95 LETTER FROM Jim Young to John Womack (OCC 11303)

TEXT: Dear Mr. Young:

This is in reply to your FAX of October 17, 1995, asking for interpretations of Motor Vehicle Safety Standard No. 108, as in relates to "customer specifications for options incorporated into, or in addition to FMVSS lighting." You have described these options as:

"Brake override circuit for rear facing warning lights. The rear warning lights flash as warning lights until the brakes are applied, at which time they become stead burn. This option is in addition to the standard brake lights. If this is acceptable, should the lights be required to meet all requirements of stop lights? (ie.; maximum luminous intensity, color, etc. . .)"

As you clarified in a phone conversation with Taylor Vinson of this Office on November 2, the "rear facing warning lights" are part of the ambulance lighting system which is not a system required by Standard No. 108. This option is permissible. Although there is no Federal legal requirement that governs the performance of ambulance warning systems, we recommend that the rear facing warning lights are red, the required color for stop lamps, inasmuch as the intent seems to be provide an additional indication that the brake have been applied.

"Brake Enhancer. Standard or additional stop lights are made to flash on/off several times before going steady burn."

This is not permissible. Standard No. 108 requires all stop lamps to be steady burning.

"Back-up alert strobes. Rear facing high intensity strobe lights that are activated when the gearshift lever is placed into reverse gear."

Optional equipment is permissible if it does not impair the effectiveness of lighting equipment required by the standard. You have not indicated the color of the strobe lamps. If they are red or amber, they could cause confusion in the eyes of an observer when operated simultaneously with the steady burning

P2

white backup lamp. There is a lesser possibility of confusion if they cast a white light, as long as they do not mask the steady burning backup lamp. In that event, the strobes could be fitted to the ambulances.

"Taillight flashers. Taillights or brake lights are flashed alternate to backup lights until brakes are applied, at which time they go steady burn. The option at times may be requested to only work of the rear doors on the ambulance are open."

This is not permissible. Standard No. 108 requires taillamps as well as stop lamps to be steady burning, under all circumstances.

If you have further questions, you may refer them to Taylor Vinson (202-366-5263).

Sincerely,