ID: nht91-3.22

DATE: April 16, 1991

FROM: Keith Salsman -- Independent Inventor

TO: Paul Jackson Rice -- Chief Counsul, NHTSA

COPYEE: Robert York

TITLE: None

ATTACHMT: Attached to letter dated 5-8-91 from Paul Jackson Rice to Keith Salsman (A37; Std. 108)

TEXT:

I am an independent inventor seeking a Letter of Interpretation concerning a type of brake light which I have spent several years working on and currently have patent pending status. During that time I have been in contact with Dr. Carl Clark, inventor contact for NHTSA, and more recently Mr. Dick Stromboten who replaced him due to his retirement. I have also talked briefly with Kevin Cavey.

The brake light device, which I call the Braking Intensity Array, is a high mount brake light designed to effectively alert a following car as to the braking status of the forward car. The light is an array of lights that light up first in the center, exactly as the current high mount brake lights, in response to any pressure on the brake pedal. However, if any actual braking occurs then the lights on either side of the center lights will respond appropriately with the adjacent lights lighting under mild braking force, the lights next to them under a stronger braking force, the next lights under an even stronger braking force, and the outer most lights lighting only under a very strong braking force such as emergency braking. Thus the light lights in both directions from the center. Research has indicated that this is very easily interpreted by someone completely unfamiliar with the device.

During the developmental process I have tried to insure absolute compliance with any rule, regulation, or past safety concern. The center lights of the array are wired directly to the current brake light switch and will comply with the regulations on high mount brake lights in the Code of Federal Regulations 571 section 108. The rest of the array is controlled by a separate device which is also connected to the brake switch and will not operate independently. There are fail safe measures to insure that the light will always operate the same regardless of vehicle incline or speed. In addition, as per Dr. Clark's suggestions, the light's response time to various braking forces will be very close to 3 milliseconds which is quick enough to give the light "Real Value" and not just "Perceived Value".

In the past year I have approached several companies with my idea. Most are interested but unwilling to pursue anything because of what they called "too much government involvement" to overcome. Recently NAPA Auto Parts has expressed a keen interest, as well as TRUCK-LITE. Mr. Robert York of TRUCK-LITE has sent me an honest non-disclosure agreement and has given a favorable response. He told me that he will send a Request for a Letter of Interpretation as well. However, since he has signed a non-disclosure it is difficult for him to be specific. Therefore, I have submitted this request in addition to his.

The General Estimates System of the Department of Transportation has on record in 1988 a total of 6,875,500 Police Reported Roadway Accidents. A total of 1,622,000 were reported as Rear End Collisions. Many more of these roadway accidents could be of a secondary nature to a Rear End Collision, for example, a vehicle swerved to avoid a rear end collision and struck another object. Approximately 500,000 of the Rear End Collisions involved minor or moderate injury and 1,962 involved fatalities. The most common injury involved spinal trauma or whiplash. This injury usually persists long after the accident. High-mount headrests are installed as a safety feature now to avoid this.

A great majority of these Rear End Collisions occurred in our cities during periods of heavy traffic causing traffic jams and lost working hours. As the traffic continues to increase in the cities and urban areas, we can expect the number of such rear end collisions to increase substantially.

The following articles of the Department of Transportation Code of Federal Regulations on lamps, reflective devices and associated equipment are concerned with high-mount brake lights. In S2, article 571.08, it states:

Purpose. The purpose of this standard is to reduce traffic accidents and deaths and injuries resulting from traffic accidents, by providing adequate illumination of the roadway, and by enhancing the conspicuity of motor vehicles on the public roads so that their presence is perceived and their signals understood, both in daylight and in darkness or other conditions of reduced visibility.

In S5.1.1.27 of the same article, it states:

Each passenger car manufacture on or after September 1,1985, shall be equipped with a high-mounted stop lamp which: a) Shall have an effective projected luminous area not less than 4 1/2 square inches.

b) Shall have a signal visible to the rear through a horizontal angle from 45 degrees to the left to 45 degrees to the right of the longitudinal axis of the vehicle.

c) Shall have a the minimum photometric values in the amount and location listed in Figure 10.

d) Need not meet the requirements of paragraphs 3.1.6 Moisture, 3.1.7 Dust Test and 3.1.8 Corrosion Test of SAE Recommended Practice J186a if it is mounted inside the vehicle. e) Shall provide access for convenient replacement of the bulb without the use of special tools.

In S5.3.1.8: Each high-mounted stop lamp shall be mounted with its center on the vertical centerline of the passenger car as the car is viewed from the

rear. The lamp may be mounted at any position on the centerline, including the glazing. If the lamp is mounted inside the vehicle, means shall be provided to minimize reflections from the light of the lamp upon the rear window glazing that might be visible to the driver when viewed directly or indirectly in the rearview mirror. If the lamp is mounted below the rear window, no portion of the lens shall be lower than 6 inches below the rear window on convertibles, or 3 inches on other passenger cars.

In S5.4.1:

Two or more lamps, reflective devices or items of associated equipment may be combined if the requirements for each lamp, reflective device and item of associated equipment are met, except that no clearance lamp may be combined optically with any tail lamp or identification lamp and no high-mounted stop shall be combined with any other lamp or reflective device.

In S5.5.4:

The stop lamps on each vehicle shall be activated upon application of the service brakes. The high-mounted stop lamp on each passenger car shall be activated only upon application of the service brakes.

In S5.5.10:

b) High-mounted stop lamps on passenger cars manufactured on or after August 1, 1984, but before September 1, 1986, may flash when the hazard warning system is activated.

These are all references to high-mounted brake lights in the Code of Federal Regulations.

I respectfully submit that my Braking Intensity Array can be manufactured according to the regulations on high-mounted brake lights, and if so manufactured would not violate any of those rules or regulations nor would it deviate from the spirit, intent, or purpose of the Federal Code of Regulations.

In conclusion the brake light described above should help to reduce rear end collisions by alerting the car behind as to the braking condition of the vehicle. Also in congested areas of traffic it will help to keep traffic flowing more smoothly. This is due to the overreaction of many drivers to the brake lights of the car ahead. In many cases a driver may rest his foot on the brake with no braking pressure, however the car following sees the brake light come on and applies some braking force. The next car applies even more force, and so on until traffic is forced to stop. As traffic continues to increase this problem will become greater. This has been recognized and there has been some work done to install computers in cars to alert the computer in the following car as to the braking condition. Why not give the driver the information first?

ID: 1786y

The Honorable Leon E. Panetta
House of Representatives
Washington, DC 20515

Dear Mr. Panetta:

This letter responds to your inquiry on behalf of your constituent, Mr. Botelho. You asked whether Federal regulations require mirrors to be placed on the right side of vehicles and whether such mirrors must be convex in nature. Mr. Botelho expressed his objection to requiring convex mirrors, because he believes convex mirrors distort images and cause objects to appear further away than they actually are. I am pleased to have this opportunity to explain this requirement and its background for you.

Standard No. 111, Rearview Mirrors (49 CFR /571.111, copy enclosed)) establishes performance and location requirements for the rearview mirrors installed in new vehicles. Specifically, a passenger car whose inside rearview mirror does not meet the field of view requirements of section S5.1.1 must have an outside mirror on the passenger side of either unit magnification or a convex mirror. In a September 2, 1982 final rule amending Standard No. 111, the National Highway Traffic Safety Administration (NHTSA) explained that convex mirrors offer safety benefits by providing an expanded field of view to the rear, thereby reducing the need for the driver to turn around to view the rear directly. On the other hand, some users of convex mirrors that were used to the images shown by conventional plane mirrors incorrectly perceived that the object shown in the convex mirror was further to the rear than it actually was. Additionally, some users of convex mirrors experienced double vision, eyestrain, and nausea. After considering these potential advantages and disadvantages, NHTSA amended Standard No. 111 so that it does not require any vehicle to be equipped with convex mirrors, but it permits the use of convex mirrors on the passenger side of cars and light trucks, provided that the convex mirror meets certain additional requirements.

The additional requirements applicable to convex mirrors on the passenger side of cars and light trucks are:

1. A maximum radius of curvature for the convex mirror. This limits the range of convexities to which drivers will be exposed. It also ensures that the field of view will be noticeably greater than for a plane mirror.

2. A minimum radius of curvature for the convex mirror. This ensures that the image size in the convex mirror will be adequate and distortion will not be excessive.

3. A stringent maximum permissible variation in the radius of curvature over the surface of the convex mirror. This requirement, which is more stringent than the European requirement in this area, also ensures that convex mirrors will have low distortion.

4. A warning etched on the convex mirror that objects shown in the mirror are closer than they appear. This requirement ensures that the driver who may not be familiar with convex mirrors will not be misled by the image size of the convex mirror and the apparent distance to the object.

Hence, we agree with Mr. Botelho that the areas he has identified are potential problems unique to convex mirrors. However, our standard includes special requirements for convex mirrors to minimize the potential problems identified by Mr. Botelho and other potential problems that were identified in research studies of convex mirrors. We are not aware of any data showing that convex mirrors that comply with those special requirements present any unacceptable problems for drivers.

I hope this information is helpful. If you have any further questions or need any additional information on this subject, please let me know.

Sincerely,

Erika Z. Jones Chief Counsel

Enclosure /ref:111 d:4/l7/89

ID: 1985-01.35

TYPE: INTERPRETATION-NHTSA

DATE: 02/22/85

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: John Humphrey -- Fleet Maintenance Division, U.S. Postal Service

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. John Humphrey General Manager Fleet Maintenance Division Office of Fleet Management United States Postal Service Delivery services Department 475 L'Enfant Plaza, SW Washington, D.C. 20260-7200

This is in response to your letter of January 15, 1985, to Taylor Vinson of this office asking for a waiver of the maximum height requirement so that the Postal Service may install center stop lamps on its new delivery trucks mounted from 75 to 83 inches above the road surface.

You do not need an exemption in order to install the lamp at the height you desire. First, Standard No. 108 requires the installation of a center high mounted stop lamp on passenger cars only, and not on trucks. Secondly, the 72-inch limitation on stop lamp mounting height imposed by Standard No. 108 for stop lamps applies only to the stop lamps that are mounted on either side of the vertical centerline. There is no limitation on the mounting height of the center lamp, when required on a vehicle, or prohibition against mounting it above 72 inches on a vehicle that is not required to have it.

We appreciate the interest of the Postal Service in reducing rear end accidents but would like to point out that the efficacy of the lamp on vehicle other than passenger cars is unknown. Our studies showed that the lamp was most effective at the approximate eye height of the driver in a following vehicle, and also as an alert to the driver behind who saw the highmounted light through the intervening car. Thus, the Postal Service with its lights mounted above the rear door should not expect its vehicles in service necessarily to replicate this agency's test experience.

Sincerely,

Original Signed By

Frank Berndt Chief Counsel

January 15, 1985

Mr. Taylor Vinson, Legal Counsel Room 5219 - FMVSS - 108 NHTSA - U.S. Department of Transportation 400 7th Street, S.W. Washington, D.C. 20590

Dear Mr. Vinson:

The U.S. Postal Service is in the process of testing and procuring a new Long Life Vehicle (LLV). These vehicles are light delivery trucks and will be used primarily for residential mail delivery and collection and will replace the vehicle (Jeep) presently used for this function.

In the interest of safety we have required a high center mounted brake light on these units. Since the units will be slightly larger than the current vehicle the high mounted brake light will exceed the maximum of seventy-two (72) inches from the roadway as required by Federal Motor Vehicle Safety Standards, Part 511, 108 Table IV Location of Required Equipment.

Due to the configuration of the proposed LLV the center mounted stop lamp will be between 78 and 83 inches from the roadway at curb weight. I have enclosed a photo of the three units we are currently testing, so that you might have a better understanding of the stop lamp location.

We are requesting a waiver to this requirement to permit placement of a center mounted stop lamp on these vehicles. Your assistance will be appreciated.

Sincerely,

Mr. John Humphrey General Manager Fleet Maintenance Division Office of Fleet Management

ID: nht87-2.52

TYPE: INTERPRETATION-NHTSA

DATE: 07/13/87

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: JACK DE NIJS DERONDE CASINGS, LTD.

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 12/09/88 FROM ERIKA Z. JONES -- NHTSA TO DONALD N. STAHL RE MCCOY TIRE SERVICE CENTER D.A. NO CF 696 REDBOOK A33, STANDARD 119, PART 574; UNDATED LETTER FROM JOHN T. FORTH AND DONALD N. STAHL TO ERIKA Z. JONES -- NHTSA RE MCCOY TIRE SERVICE CENTER D.A. NO CF696, OCC 1749; LETTER DATED 03/01/88 FROM DAVE TAYLOR TO JOHN T. FORTH, EXHIBIT 1; LETTER DATED 05/19/87 FROM JACK DENIJS TO ERIKA Z. JONES, SUBJECT COVERED DOT NUMBERS ON REMANUFACTURED TRUCK CASINGS; DRAWING OF TI RE DATED 01/14/88, MODESTO CITY SCHOOLS TIRE INFORMATION, EXHIBIT 3

TEXT: Dear Mr. De Nijs:

This responds to your letter to this office, in which you asked whether you could import into the United States foreign truck tire casings that do not have either a DOT symbol or a tire identification number on the sidewall. You stated in your letter th at you would either retread these tires yourself or sell them to other retreaders to be retreaded. Subject to certain conditions, you may import these casings.

The general provisions dealing with the importation of items of motor vehicle equipment such as tires are set forth in section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(1)(A)). That section makes it unlawful fo r any person to import into the United States any item of motor vehicle equipment manufactured on or after the date that an applicable Federal motor vehicle safety standard takes effect, unless the equipment (tire) is in conformity with the standard. Fe deral Motor Vehicle Safety Standard No. 119, New Pneumatic Tires for Vehicles Other Than Passenger Cars (49 CFR @ 571.119) took effect on March 1, 1975. Standard No. 119 requires that truck tires and other tires for use on vehicles other than passenger cars pass certain performance and be labeled with certain safety information, including the tire identification number. The tire manufacturer is required to certify that each of its truck tires complies with Standard No. 119 by permanently molding the s ymbol DOT into or onto the sidewall of the tire. Thus, any tires without a DOT symbol on the sidewall that were manufactured on or after March 1, 1975 would not be in compliance with Standard No. 119 and could not legally be imported into the United Sta tes.

However, the agency reached a somewhat different conclusion with respect to the permissibility of importing truck tire casings in a June 18, 1981 letter from former Chief Counsel Frank Berndt to Mr. Roy Littlefield (copy enclosed). In that letter, the a gency concluded that truck tire casings that have less than 2/32 inch of tread and which are imported solely to be retreaded are not "items of motor vehicle equipment" within the meaning of section 108(a)(1)(A) of the Safety Act. This conclusion

means that truck tire casings that meet these conditions may be imported into the United States. Please note that you cannot legally import any non-complying truck tire casings that have 2/32 inch or more of tread or any non-complying casings that will not be retreaded before they are used on the public roads.

If you have any further questions on this subject, please feel free to contact Steve Kratzke of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

ENCLOSURE

ID: nht89-1.75

TYPE: INTERPRETATION-NHTSA

DATE: 04/17/89

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: LEON E. PANETTA -- HOUSE OF REPRESENTATIVES

TITLE: NONE

ATTACHMT: LETTER DATED 02/04/89 FROM LEON E., PANETTA TO ERIKA Z. JONES

TEXT: Dear Mr. Panetta:

This letter responds to your inquiry on behalf of your constituent, Mr. Botelho. You asked whether Federal regulations require mirrors to be placed on the right side of vehicles and whether such mirrors must be convex in nature. Mr. Botelho expressed hi s objection to requiring convex mirrors, because he believes convex mirrors distort images and cause objects to appear further away than they actually are. I am pleased to have this opportunity to explain this requirement and its background for you.

Standard No. 111, Rearview Mirrors (49 CFR @ 571.111, copy enclosed)) establishes performance and location requirements for the rearview mirrors installed in new vehicles. Specifically, a passenger car whose inside rearview mirror does not meet the fiel d of view requirements of section S5.1.1 must have an outside mirror on the passenger side of either unit magnification of a convex mirror. In a September 2, 1982 final rule amending Standard No. 111, the National Highway Traffic Safety Administration ( NHTSA) explained that convex mirrors offer safety benefits by providing an expanded field of view to the rear, thereby reducing the need for the driver to turn around to view the rear directly. On the other hand, some users of convex mirrors that were u sed to the images shown by conventional plane mirrors incorrectly perceived that the object shown in the convex mirror was further to the rear than it actually was. Additionally, some users of convex mirrors experienced double vision, eyestrain, and naus ea. After considering these potential advantages and disadvantages, NHTSA amended Standard No. 111 so that it does not require any vehicle to be equipped with convex mirrors, but it permits the use of convex mirrors on the passenger side of cars and lig ht trucks, provided that the convex mirror meets certain additional requirements.

The additional requirements applicable to convex mirrors on the passenger side of cars and light trucks are:

1. A maximum radius of curvature for the convex mirror. This limits the range of convexities to which drivers will be exposed. It also

ensures that the field of view will be noticeably greater than for a plane mirror.

2. A minimum radius of curvature for the convex mirror. This ensures that the image size in the convex mirror will be adequate and distortion will not be excessive.

3. A stringent maximum permissible variation in the radius of curvature over the surface of the convex mirror. This requirement, which is more stringent than the European requirement in this area, also ensures that convex mirrors will have low distortio n.

4. A warning etched on the convex mirror that objects shown in the mirror are closer than they appear. This requirement ensures that the driver who may not be familiar with convex mirrors will not be misled by the image size of the convex mirror and the apparent distance to the object.

Hence, we agree with Mr. Botelho that the area he has identified are potential problems unique to convex mirrors. However, our standard includes special requirements for convex mirrors to minimize the potential problems identified by Mr. Botelho and oth er potential problems that were identified in research studies of convex mirrors. We are not aware of any data showing that convex mirrors that comply with those special requirements present any unacceptable problems for drivers.

I hope this information is helpful. If you have any further questions or need any additional information on this subject, please let me know.

Sincerely,

ENCLOSURE

ID: 1985-04.27

TYPE: INTERPRETATION-NHTSA

DATE: 11/15/85

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: William E. Sandham -- Sales Manager, OEM Division, Velvac, Inc.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. William E. Sandham Sales Manager, OEM Division Velvac, Inc. 2900 South 160th Street New Berlin, WI 53151

Thank you for your letter of May 21, 1985, concerning the vertical adjustment of rearview mirrors for trucks. You asked us to clarify whether the standard requires a mirror both to tilt, as shown in your sketch "A," and to move up and down its mounting bracket, as shown in your sketch "B." As discussed below, a truck mirror can meet the adjustment requirement by either tilting or by moving up and down its mounting bracket.

The agency has not specified the means used to provide a vertical adjustment. We would consider a mirror which tilts, as shown in your sketch "A," or which moves up and down on its mounting bracket, as shown in your sketch "B," as meeting the adjustment requirement. You should know that the agency has interpreted this vertical adjustment requirement for trucks to mean that adjustment with tools is allowed. The use of tools is justified because trucks and buses are generally driven for longer periods of time by the same driver and thus the mirror does not have to be continually adjusted.

Please note that S6.1(a) of Standard No. 111 also permits trucks with a GVWR of 10,000 pounds or less to be equipped with rearview mirrors which meet the performance requirements for passenger cars in section S5, instead of the requirements for trucks in S6.1(b), S7, or S8. If the passenger car specifications ar; chosen, the driver must be able to adjust the inside and outside rearview mirrors in both vertical and horizontal directions by tilting them. The agency has not permitted the use of tools for adjusting passenger car mirrors, since passenger cars are often driven by different drivers who will need to quickly and easily adjust their mirrors. A mirror mounted on a universal ball socket joint, for example, meets this requirement. In this situation, the vertical tilting adjustment shown in your sketch "A" would appear to comply as long as that mirror could also be adjusted horizontally by tilting. The vertical sliding adjustment shown in sketch "B" apparently would not meet this requirement because it appears to require the use of tools to make the adjustment.

A copy of the current version of Standard No. 111 is enclosed. I hope this information is helpful to you.

Sincerely, Erika Z. Jones Chief Counsel Enclosure

May 21, 1985 Legal Council FMVSS III - Room 5219 National Highway Traf. Safety Adm. U.S. Dept of Transportation 400 7th St. S.W. Washington, DC 20590

Gentlemen:

We are seeking clarification on the wording in MVSS III pertaining to mirror adjustment, particularly the terminology regarding "VERTICAL ADJUSTMENT" of truck mirrors.

Our impression is that this standard refers to the adjustment of the vertical plane of vision on the mirror head as shown on the attached sketch "A".

One of our customers has a question regarding this interpretation and is wondering if the standard is also requiring a vertical adjustment of the mirror head, physically up and down, on the loop or mounting bracketry, as shown in sketch "B".

We would appreciate your comments on this matter and also the latest revision of MVSS III for our records.

Thank you. Yours truly, William E. Sandham Sales Manager OEM Division cc: Mr. R. Brester WES/ds Attachments

ID: nht79-3.34

DATE: 06/18/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Cars & Concepts, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your May 21, 1979, letter concerning the marking requirements for vehicle windshields having shade bands. You asked whether the "A S1" marking symbol required by Safety Standard No. 205, Glazing Materials, can be placed on the tint band itself rather than on the glazing material below the band, if the tint band is a flexible sheet applied on top of the glazing.

Safety Standard No. 205 incorporates by reference the American National Standard "Safety Code for Safety Glazing Materials", ANS Z26. The ANS Z26 standard requires special additional markings for glazing that has shade bands or tinted areas:

"Glazing materials, which in a single sheet of material, are intentionally made with an area having a luminous transmittance of not less than 70 percent (Test No. 2), adjoining an area which has less than 70-percent luminous transmittance, shall be permanently marked at the edge of the sheet to show the limits of the area which is intended to comply with Test No. 2. The markings shall be A S1 or A S2, etc., the direction of the arrow indicating the portion of the material which complies with Test No. 2 and the number indicating the item with which that portion of the sheet complies . . . ."

You will note from the quoted portion of this specification that the special marking is only required if the tinted shade band area of the windshield has a luminous transmittance of less than 70 percent. Your letter states that the transparent windshield tint band that you intend to use allows 70 percent light transmission. Therefore, you would not be required to use the "A S1" special marking either on the band itself or on the glazing.

For removable tint bands of this type that do not have a 70 percent light transmission, however, the agency would permit the "A S1" marking to be on the tint band itself rather than on the underlying glazing, provided the marking is located at the lowest possible portion of the tint band.

Sincerely,

ATTACH.

May 21, 1979

Joseph J. Levin -- Chief Council, N.H.T.S.A.

Dear Mr. Levin:

Cars & Concepts is preparing a vehicle for 1980 production which incorporates a transparent windshield tint band. This band would allow 70% light transmission across its width and be located in accordance with SAE J-100.

This band would be applied to a piece of untinted glass and this condition forms the basis for my question. If we install a shade band across the top of a vehicle's windshield, are we required to sandblast the designation "AVSI" onto the glass below the band (I understand it is cited through reference in FMVSS No. 205)?

If this "AVSI" notice is required on untinted glass when a shade band is applied, I propose that it should be on the band itself as it is only when the band is on the car (it would be possible to remove the band) that this notice is required.

The N.H.T.S.A.'s decision on this point is critical to our project timing as brochure shots are scheduled and the addition or deletion of this component must be made prior to brochure release. Because of this your response as soon as possible will be greatly appreciated.

Enclosed is a photograph of a vehicle with a prototype version of the mentioned tint band which I feel may clarify our question. Please call if any point is unclear.

Sincerely, Moe Pare -- Director of Design

Encl.

cc: D. Draper; R. Ryan

(Graphics omitted)

ID: nht74-2.22

DATE: 06/12/74

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Southern Railway System

TITLE: FMVSS INTERPRETATION

TEXT: In your letters of January 10, 1974, and May 17, 1974, you have asked if a trailer would comply with S5.8 of Standard No. 121, Air brake systems, ("have a parking brake system. . . when the air pressure in the supply line is at atmospheric pressure") if its parking brake system contained a valve that allows manual release of the parking brake with the supply line at atmospheric pressure but automatically resets itself when the supply line is pressurized, so that the parking brake system operates as specified by S5.8. Such a valve would permit limited motion of trailers on flat cars to cushion shock experienced during transit.

Such a valve does not appear to conflict with the intent of S5.8 that the parking brake system apply when the supply line is at atmospheric pressure. The requirement is not intended to interfere with intentional manual release of the parking brakes after automatic application has occurred. The danger of inadvertent disablement of the parking brake system during subsequent highway travel is avoided by the automatic features which would return the system to normal operation as soon as the trailer is connected to a source of air pressure, i.e., a tractor.

Sincerely,

ATTACH.

May 17, 1974

Richard B. Dyson -- Assistant Chief Counsel for Regulations, National Highway Traffic Safety Administration, U. S. Department of Transportation

Dear Mr. Dyson:

Please refer to my letter dated January 10, 1974, and I also refer to my telephone conversations of May 17 and earlier with Mr. (Illegible Word) of your office, concerning the problems created for trailers to be used on railroad flat cars by the new requirements for parking brakes.

Attached is a memorandum dated May 17, 1974 from Southern Railway's Assistant Vice President - Engineering & Research C. E. Webb, explaining why there is a need for a parking brake system on a trailer which will allow it to move longitudinally along a flat car for a short distance during impact. Read literally, Section S5.8 of the new regulations would require a trailer to be equipped with a parking brake designed so that the trailer would be incapable of this short longitudinal movement on impact. Mr. Webb in his memorandum proposes parameters for a device, to be developed by the manufacturers and approved by DOT if necessary, which would achieve the purpose of the new regulation when the trailer was in over-the-road use, while at the same time meeting the need for a means to "cut out" the parking brake when the trailer is on a rail car. Mr.

Webb envisions a fail-safe device. I might add that by proposing the device described by Mr. Webb, Southern intends to take no exception to a change in the rules which would be more liberal, that is, allow devices to be put on trailers that would also allow the manual disabling of the parking brake in other situations where it may be desirable, e.g., in freight yards during hostling.

As I said in my January 10 letter, we believe @ 5.8 does not forbid installation of a device like that described by Mr. Webb. However, in order to interest manufacturers in developing the device, we feel it important that your agency indicate that it would be proper and permissible under your regulations. Therefore, we would appreciate receiving advice from you to that effect, if that is the view of your agency.

Thank you.

Yours sincerely,

William P. Stallsmith, Jr. Senior General Attorney -- SOUTHERN RAILWAY SYSTEM

ID: nht94-7.47

DATE: March 10, 1994

FROM: Norman Duncan -- President, Study-Tech, Inc.

TO: Rodney Slater -- Administrator, FHA Transportation Department

TITLE: None

ATTACHMT: Attached to letter dated 5/18/94 from John Womack to Norman Duncan (A42; VSA 108(a)(2)(A); Std. 108) and letter dated 10/22/93 from John Womack to Thomas G. Cehelnik

TEXT:

The purpose of this letter is to request from your office AN INTERPRETATION OF THE EXISTING VEHICLE CODE as it may apply to a safety-warning system that our corporation has devised.

The system:

- Is designed to operate at the rear of vehicles to warn the cars following that they are slowing down.

- Can be attached to either the existing brake lights of the vehicle, or could use separately mounted "warning lights" mounted at the rear- deck level and facing toward the back of the vehicle.

- Will automatically be activated the moment the vehicle "begins to slow-down" due to deceleration.

There are many benefits to be derived from the use of this device.

For example:

- There are critical time intervals between when a driver notes an emergency ahead and when the driver reacts. Precious seconds are lost before the driver's reflex action activates the brake lights.

(Note: Using the "Early-Warning Slow-Down Safety Light", the driver following would see the warning light at the precise moment that the vehicle begins to slow.)

According to statistics gathered from several state's traffic and crash facts books, (Eg. "Illinois Crash Facts and Statistics - 1992), about 25% of all collisions involving two vehicles are rear-end type accidents. This is an alarming fact! This type of accident is in the category of "Could-be-Avoided" if drivers were more alert, or a warning signal was given at the moment of deceleration of the vehicle in front.

That degree of being "alert" in normal traffic is the foundation for our "Early-Warning Slow-Down Safety Light". We envision this device to be the latest in an emerging field of new safety devices. The newest safety devices include: the air bags, the rear-deck additional "stop light", improved head lamps and Anti-locking Brake Systems. Soon, we understand, General Motors will install running lights for their cars that will be "on" whenever the ignition is turned on. All of these

recently developed safety features are designed to bring about higher standards for safety for our nation's highways. Our device, we feel, is another important extension of this concern to make our U.S. vehicles as safe as possible.

We need your assistance and look forward to your answers to the following questions:

A. Can current vehicle codes be interpreted to allow for an automatic signal when a vehicle begins to slow-down?

B. If vehicle codes do not allow for this type of device, would you or some member of your staff be willing to assist us in an effort to develop plans to allow this type of device?

C. Would you or members of your staff be interested in attending a demonstration of the prototype of the safety device? (To be arranged.)

It is our goal to apply for a patent for this device because it represents important "new" technology in this particular field.

An early response from your office would be appreciated very much. We look forward to hearing from you.

ID: nht94-1.77

TYPE: Interpretation-NHTSA

DATE: March 10, 1994

FROM: Norman Duncan -- President, Study-Tech, Inc.

TO: Rodney Slater -- Administrator, FHA Transportation Department

TITLE: None

ATTACHMT: Attached to letter dated 5/18/94 from John Womack to Norman Duncan (A42; VSA 108(a)(2)(A); Std. 108) and letter dated 10/22/93 from John Womack to Thomas G. Cehelnik

TEXT:

The purpose of this letter is to request from your office AN INTERPRETATION OF THE EXISTING VEHICLE CODE as it may apply to a safety-warning system that our corporation has devised.

The system:

- Is designed to operate at the rear of vehicles to warn the cars following that they are slowing down.

- Can be attached to either the existing brake lights of the vehicle, or could use separately mounted "warning lights" mounted at the rear- deck level and facing toward the back of the vehicle.

- Will automatically be activated the moment the vehicle "begins to slow-down" due to deceleration.

There are many benefits to be derived from the use of this device.

For example:

- There are critical time intervals between when a driver notes an emergency ahead and when the driver reacts. Precious seconds are lost before the driver's reflex action activates the brake lights.

(Note: Using the "Early-Warning Slow-Down Safety Light", the driver following would see the warning light at the precise moment that the vehicle begins to slow.)

According to statistics gathered from several state's traffic and crash facts books, (Eg. "Illinois Crash Facts and Statistics - 1992), about 25% of all collisions involving two vehicles are rear-end type accidents. This is an alarming fact! This type o f accident is in the category of "Could-be-Avoided" if drivers were more alert, or a warning signal was given at the moment of deceleration of the vehicle in front.

That degree of being "alert" in normal traffic is the foundation for our "Early-Warning Slow-Down Safety Light". We envision this device to be the latest in an emerging field of new safety devices. The newest safety devices include: the air bags, the rear-deck additional "stop light", improved head lamps and Anti-locking Brake Systems. Soon, we understand, General Motors will install running lights for their cars that will be "on" whenever the ignition is turned on. All of these

recently developed safety features are designed to bring about higher standards for safety for our nation's highways. Our device, we feel, is another important extension of this concern to make our U.S. vehicles as safe as possible.

We need your assistance and look forward to your answers to the following questions:

A. Can current vehicle codes be interpreted to allow for an automatic signal when a vehicle begins to slow-down?

B. If vehicle codes do not allow for this type of device, would you or some member of your staff be willing to assist us in an effort to develop plans to allow this type of device?

C. Would you or members of your staff be interested in attending a demonstration of the prototype of the safety device? (To be arranged.)

It is our goal to apply for a patent for this device because it represents important "new" technology in this particular field.

An early response from your office would be appreciated very much. We look forward to hearing from you.