Interpretation 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?