ID: nht94-2.31

TYPE: Interpretation-NHTSA

DATE: April 12, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Eldon J. McLauchlin -- President, Valley Automotive Specialties, Inc. (Spokane, Washington)

TITLE: None

ATTACHMT: Attached to letter dated 1/25/94 from Eldon J. McLauchlin to John Womack (OCC 9612)

TEXT:

This responds to your January 25, 1994, letter asking about how this agency's regulations might apply to your product, the Automated Fire Extinguisher System (AFES). You state that your product's purpose is to allow the operators and occupants of a vehi cle to exit safely in the event of a fire. Apparently, the AFES sensors will detect smoke and heat and respond by automatically opening some sort of control valve, whereupon a manifold assembly with "strategically placed directional nozzles" will flood the passenger compartment with some sort of fire extinguisher/retardant. You do not state what kind of fire extinguisher/retardant is used. You explain that the automatic nature of this system will provide time to extract even an unconscious or incapac itated operator or occupant.

Apparently, the AFES has wide applicability. You explain that the AFES proto-type can be installed in a car, truck, boat, RV, or bus or other vehicle running on a 12 volt battery. Apparently you will modify the AFES so that it will run off the 110 volt current in homes and commercial buildings.

I am pleased to have this opportunity to explain our regulations. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards (FMVSS'S) for new motor vehicles and new items of motor vehicle equipment. Section 102(4) of the National Traffic and Motor Vehicle Safety Act (the "Safety Act") defines, in relevant part, the term "motor vehicle equipment" as:

any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component OR AS ANY ACCESSORY, or addition to t he motor vehicle... (emphasis added).

In determining whether an item of equipment is considered an accessory, NHTSA applies two criteria. The first criterion is whether a substantial portion of the expected use of the item is related to the operation or maintenance of motor vehicles. We de termine a product's expected use by considering product advertising, product labeling, and the type of store that retails the product, as well as available information about the actual use of the product. The second criterion is whether the product is i ntended to be used principally by ordinary users of motor vehicles. If the product satisfies both criteria, then the product is considered to be an "accessory" and thus is subject to the provisions of the Safety Act.

Applying these criteria to the AFES, it appears that this product would be an accessory and thus an item of motor vehicle equipment under the Safety Act. Based on our understanding of the product, it appears that a substantial

portion of the expected use of the AFES system relates to motor vehicle operation. The system is intended to protect anyone occupying a vehicle when a fire occurs. Also, it appears that the product would typically be used by ordinary users of motor veh icles.

While it appears that the AFES system is an item of motor vehicle equipment, NHTSA has not issued any standards for such a device. Nevertheless, there are other Federal laws that indirectly affect the manufacture and sale of your product. You as the pr oduct's manufacturer are subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that the manufacturer or NHTSA determines that the product contains a safety related defect, the manufacturer would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge.

We have some concerns about the safety impacts if the AFES were to activate while the vehicle is moving. Is it possible, for example, that a driver smoking in the car on a hot day could accidentally set off the sensors, or that they could malfunction sp ontaneously? Although we do not know what will be coming through the nozzles (fluid, foam, and inert gases are common fire extinguishing agents), we are concerned that AFES activation could cause the driver to lose control in what is otherwise a control lable situation. We urge you to thoroughly consider these and other factors that could affect the safety of motor vehicle operation.

If the AFES were installed by a vehicle manufacturer as original equipment, the vehicle manufacturer would have to certify that the vehicle with the AFES installed complies with all FMVSS's. Among the FMVSS's that might be affected by certain AFES insta llations are Standard No. 201, "Occupant Protection in Interior Impact," and Standard No. 208, "Occupant Crash Protection."

A commercial business that installs the AFES system would also be subject to provisions of the Safety Act that affect modifications of new or used vehicles. Section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)) provides that:

No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable F ederal motor vehicle safety standard.

This means that a manufacturer, distributor, dealer, or motor vehicle repair business must not install your device if the system renders inoperative the vehicle's compliance with the FMVSS's. For instance, compliance with Standard No. 208 might be degra ded if it were necessary to mount the AFES manifold or directional nozzles in front of the driver or passenger. Any violation of this "render inoperative" prohibition would subject the violator to a potential civil penalty of up to $1,000 for each viola tion.

Please note also that the render inoperative prohibition does not apply to modifications that vehicle owners make to their own vehicles. Thus, Federal law would not apply in situations where individual vehicle owners install the AFES in their own vehicl es, even if the installation were to result in the vehicle no longer complying with the safety standards. However, NHTSA

encourages vehicle owners not to degrade any safety device or system installed in their vehicles. In addition, individual States have the authority to regulate modifications that individual vehicle owners may make to their vehicles, so you might wish to consult State regulations to see whether your device would be permitted.

I hope this information is helpful. I am also enclosing a copy of a fact sheet titled "Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment." If you have any further questions about NHTSA's safety standards, please feel free to contact us at this address or by telephone at (202) 366-2992.

ID: nht94-2.32

TYPE: Interpretation-NHTSA

DATE: April 12, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: J. Roberts -- John H. Roberts Well Drilling Co. (Brighton, MI)

TITLE: None

ATTACHMT: Attached to letter dated 3/7/94 from J. Roberts to John Womack (OCC 9780)

TEXT:

This responds to your letter of March 7, 1994. You ask for clarification of the agency's position on HMMMV vehicles, as expressed in our letter to Senator Nunn, a copy of which I sent you on February 28.

Specifically, you ask for "the list of the specific objections your department based its recommendation on." As we explained to Senator Nunn, this agency has specifically exempted military motor vehicles from the statutory requirement that all motor veh icles be manufactured to conform to all applicable Federal motor vehicle safety standards. The standards that would otherwise cover HMMMV vehicles are those that apply to "multipurpose passenger vehicles" or to "trucks", depending upon the end configura tion of any specific HMMMV vehicle.

Thus, our objection was based on the fact that military HMMMVs are not manufactured to meet the Federal motor vehicle safety standards. We have no knowledge of the specific standards that military HMMMVs do and do not meet, since we have never asked its manufacturer to provide this information.

ID: nht94-2.33

TYPE: Interpretation-NHTSA

DATE: April 12, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Adam A. Freund -- Manager, Testing Services, Standards Testing Laboratories, Inc. (Massillon, OH)

TITLE: None

ATTACHMT: Attached to letter dated 1/10/94 from Adam A. Freund to Walter Myers (OCC 9556)

TEXT:

This responds to your letter addressed to the attention of Walter Myers of my staff in which you asked whether Table II of Federal Motor Vehicle Safety Standard (FMVSS) No. 119, New pneumatic tires for vehicles other than passenger cars, contains certain errors.

You pointed out in your letter that Table I of FMVSS 119 specifies a plunger diameter of 5/16 inch for motorcycles, and 3/4 inch for 12-inch or smaller rims other than motorcycles. Table II, on the other hand, leaves blank the plunger diameter space, in the motorcycle column, but lists 5/16 inch plunger diameter in the 12-inch or smaller rim column. You indicated your belief that the inconsistency is due to a typographical error in those columns of Table II and asked us to confirm your interpretation.

Your observation is correct. A November 13, 1973 rule adopting Tables I and II (38 FR 31299) (copy enclosed) specifies the 5/16-inch diameter plunger for motorcycle tires, and the 3/4-inch diameter plunger for 12-inch or smaller tires and 17.5- inch or smaller light truck tubeless tires. Accordingly, the plunger diameter for the motorcycle column in Table II should read 5/16. Similarly, the 12-inch or smaller column in the current Table II is in error in specifying a plunger diameter of 5/16 inch. Th e correct plunger diameter for that column in Table II should be 3/4 inch to correspond with the plunger diameter specified for 12-inch or smaller rims in Table I.

Thank you for bringing this error to our attention. The agency will issue a correction to avoid any further confusion.

ID: nht94-2.34

TYPE: Interpretation-NHTSA

DATE: April 12, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Ted H. Richardson -- Fleet Coordinator, Priefert Manufacturing Company, Inc. (Mt. Pleasant, Texas)

TITLE: None

ATTACHMT: Attached to letter dated 12/15/93 from Ted H. Richardson to Office of Chief Counsel, NHTSA (OCC 9478)

TEXT:

This responds to your letter and telephone call to this office asking our opinion regarding Federal Motor Vehicle Safety Standard (FMVSS) No. 120, Tire selection and rims for motor vehicles other than passenger cars. Your letter referenced a telephone c onversation with Walter Myers of my staff about the applicability of FMVSS 120 to your product. As Mr. Myers informed you, the answer to your question depends on whether your product, the "Wishbone Carriage" used to position and carry the "Priefert live stock chute" is a "motor vehicle" (i.e., trailer) under our Safety Act and regulations. Based on the information we have, we believe the answer is no.

By way of background information, the National Traffic and Motor Vehicle Safety Act of 1966, 15 U.S.C. S1381, et seq. (Safety Act), authorizes this agency, the National Highway Traffic Safety Administration (NHTSA), to issue safety standards applicable t o motor vehicles. Section 102(3) (15 U.S.C. S1391(3)) of the Safety Act defines motor vehicle as:

(A)ny vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails.

NHTSA further defines "trailer" in 49 CFR 571.3 as:

(A) motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle.

Your letter enclosed a brochure containing pictures and other information relating to the livestock chute (Priefert Squeeze Chute, Model 91). The chute is farm equipment. The upper 2/3 of the chute is constructed of steel bars, while the lower 1/3 is c omposed of steel panels on both sides that can be lowered or removed. The chute comes with such accessories as head gate, tail gate, and calf table. The chute is positioned on the ground in a barnyard, feed lot, pasture, or field. It is used to channe l livestock or, with the head and/or tail gate in place, to immobilize an animal for medicating, branding, tagging, and the like. Your information also describes the carriage that transports the chute. The Wishbone Carriage is a 2-wheeled U-shaped doll y which is designed to be manually attached to special fittings on the chute.

With the carriage thus attached, the chute can be towed by vehicle to the next job site. Once at the next job site, the wheeled carriage is detached and the chute is once again placed on the ground for use.

Whether the Wishbone Carriage is a motor vehicle (trailer) depends on its on-road use. This agency has consistently held that vehicles designed and sold solely for off-road use, such as airport runway vehicles and underground mining equipment, are not c onsidered motor vehicles even though they may be operationally capable of highway travel. Vehicles that have an abnormal body configuration that readily distinguishes them from other highway vehicles and that have a maximum speed of 20 miles per hour ar e not considered motor vehicles. Agricultural equipment, such as tractors, as well as equipment that uses the highways solely to move between job sites and which typically spend extended periods of time at a single job site, are not considered motor veh icles. That is because the use of these vehicles on the public roadways is intermittent and merely incidental to their primary off-road use.

We have determined that the Wishbone Carriage is not a motor vehicle, because it appears it will be primarily used to transport the chute from job site to job site on the farm. Not being a motor vehicle, the Federal motor vehicle safety standards, inclu ding FMVSS No. 120, would not apply to your product.

Please note, however, that if the Carriage is regularly used to carry the chute from farm to farm on public roads, or is used more frequently on the public roads than the use we anticipate, the agency may reexamine the determination that the carriage is not a motor vehicle. Also, you may wish to consult your attorney for information on possible operational restrictions on your product, such as State licensing and use laws and product liability.

I hope this information is helpful to you. We have enclosed a copy of FMVSS 120 and provided you our definition of a trailer, as you requested. Should you have any further questions or need additional information, please feel free to contact Mr. Myers at this address or at (202) 366-2992.

ID: nht94-2.35

TYPE: Interpretation-NHTSA

DATE: April 12, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: J. Hulshof -- Nedap N.V. (The Netherlands)

TITLE: None

ATTACHMT: Attached to letter/fax dated 12/14/93 from J. Hulshof to Patrick Boyd (OCC 9448)

TEXT:

This responds to your letter to Mr. Patrick Boyd requesting a written interpretation concerning whether your sunroof would meet the requirements of Federal Motor Vehicle Safety Standard No. 118, "Power-Operated Window, Partition, and Roof Panel systems." I apologize for the delay in responding.

By way of background, the National Traffic and Motor Vehicle Safety Act establishes a self-certification system under which manufacturers are responsible for ensuring that their products comply with all applicable FMVSSs. We do not approve, endorse, or g ives assurances of compliance of any product. In response to manufacturers' requests for interpretations of the FMVSS's, we try, to the extent possible, to provide information that will help them make their determinations of compliance. However, these r esponses are based on information provided by the manufacturer, and are subject to the findings of actual compliance testing by the agency. Should the agency, in the future, examine your product and detect an apparent noncompliance or defect, those resu lts will control.

You explain in your letter that your power-operated sunroof (which is a power operated "roof panel system" under Standard 118) can be closed only in four circumstances. In three of these, the ignition key must be activated. In the fourth, the sunroof c an be closed when there is "Continuous operation of Central close mechanism, not capable (sic) closing the roof panel from a distance of more than 6 meters from the vehicle."

Standard 118 requires sunroofs other than those that have an automatic reversing feature to close only in certain circumstances. One of those (S4(a)) is when the key controlling the vehicle's engine is in the activated (i.e. "on", "start" or "accessory" ) position. The three circumstances you described where the ignition key must be activated to operate the sunroof appear to satisfy S4(a).

With regard to the fourth circumstance, Standard 118 also permits sunroofs to close "Upon continuous activation of a remote actuation device, provided that the...device shall be incapable of closing the (sunroof) from a distance of more than 6 meters fro m the vehicle" (S4(d)). The circumstance you described appears to satisfy S4(d). Your sunroof will close only upon continuous operation of a "Central close mechanism," and the mechanism is incapable of closing the sunroof from a distance of more than 6 meters from the vehicle.

I hope this information has been helpful. If you have any further questions, please contact Mr. David Elias of my office at the above address or by phone at (202) 366-2992.

ID: nht94-2.36

TYPE: Interpretation-NHTSA

DATE: April 12, 1994

FROM: Christopher A. Hart -- Acting Administrator, NHTSA

TO: Doug Bereuter -- U.S. House of Representatives

TITLE: None

ATTACHMT: Attached to letter dated 3/9/94 from Doug Bereuter to Howard Smolkin

TEXT:

Thank you for your letter concerning a rulemaking related to compressed natural gas (CNG) vehicle fuel systems and fuel containers. You express concern about the time it is taking to complete the rulemaking.

I fully understand your concern over this matter and want to assure you that the agency is working diligently to reach a final decision. The supplemental notice of proposed rulemaking we issued in December 1993 was an essential step toward permitting the use of CNG containers that employ new technologies. We have now reviewed the comments received on this notice and are preparing the final rule. As agency representatives explained when they met with you in December 1993, the final rule will be reviewe d by the Office of the Secretary and the Office of Management and Budget.

I hope this information is helpful and appreciate your patience in this matter.

ATTACHMENT 12/3/93

Dear Congressman Doug Bereuter:

This is in response to your November 22, 1993, letter regarding the actions of the National Highway Traffic Safety Administration in regulating the safe performance of compressed natural gas motor vehicles and fuel containers. I understand that represen tatives of the National Highway Traffic Safety Administration are scheduled to meet with you during the week of December 6 to discuss the points you raised in your letter. I think that they will be able to address your concerns at that time; however, I' d be happy to talk with you further about this if necessary.

Sincerely,

Federico Pena

ID: nht94-2.37

TYPE: Interpretation-NHTSA

DATE: April 13, 1994

FROM: Richard Kreutziger -- Executive Director, New York State Bus Distributors Ass'n.

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 4/25/94 from John Womack to Richard Kreutziger (A42; Std. 108)

TEXT:

I VERY MUCH APPRECIATE YOUR RESPONSE TO MY QUESTIONS FAXED TO YOU ON 1/12/94 AND 2/14/94. THE "APPENDIX" PROVIDED HAS AND I AM SURE WILL PROVIDE MUCH MORE BENEFIT IN TIME.

I AM FACED, NOW, WITH A NEW QUANDARY. I CERTAINLY DO NOT MEAN TO IMPOSE ADDED WORK LOAD, AND I ASSURE YOU THAT I HAVE READ AND REREAD FMVSS 571.108 - LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT, FOR MY ANSWER.

IN 571.108 SECTION S5.5.7 - REFERENCE TO VEHICLES INCLUDING BUSES, OF LESS THAN 80 INCHES OVERALL WIDTH - HAVE VERY DEFINITE WIRING PROGRAMS INCLUDED, PART (a) AND (b) - IN BOTH SUB-SECTIONS THE "MAKER LIGHTS" ARE REFERRED TO - WHICH HAVE TO BE ACTIVATED WHEN THE PARKING OR HEADLIGHT SWITCH IS ACTIVATED.

MY "QUANDARY" IS - I CAN FIND NO LIKE OR SIMILAR SECTION REQUIRING THE ACTIVATION OF SPECIFIC LIGHTS ON VEHICLES OF MORE THAN 80 INCHES IN OVERALL WIDTH.

ANY HELP AND/OR KNOWLEDGE OF A SIMILAR POSITION/FACTOR ON VEHICLES OF MORE THAN 80 INCHES IN WIDTH AS THOSE OF 80 INCHES OR LESS WILL BE GREATLY APPRECIATED.

ID: nht94-2.38

TYPE: Interpretation-NHTSA

DATE: April 14, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Robert L. Montgomery -- Safety Manager, Leprino Transportation Division, Leprino Foods (Denver, CO)

TITLE: None

ATTACHMT: Attached to letter dated 3/24/94 from Marvin A. Leach to Robert Hellmuth (OCC 9821); Also attached to letter dated 3/24/94 from Marvin A. Leach to to Robert L. Montgomery; Also attached to a letter dated 3/9/94 from Robert Montgomery to Mike Baker

TEXT:

This replies to your letter of March 9, 1994, to the Regional Office of the Federal Highway Administration (FHWA). You have questions regarding the trailer conspicuity requirements of Federal Motor Vehicle Safety Standard No. 108, a regulation of the Na tional Highway Traffic Safety Administration.

You have enclosed photos of two rear end treatments. In Photo #1, the conspicuity treatment is applied "on the doors at a height of 56 inches which is approximately 6 inches higher than the 1.25 meters (50 inches) dictated." The conspicuity treatment ap pears to extend the full width of the vehicle. In Photo #2, the reflectorized material is located "4 inches less than the 1.25 meters (50 inches) dictated." In this configuration, the conspicuity treatment has been relocated to a position between the r ear lighting units so that it no longer extends the full width of the vehicle.

Photo #1 represents the trailer as received from the manufacturer. Photo #2 represents the modifications you wish to make to the trailer. You have asked whether the configuration depicted in Photo #2 complies with Standard No. 108.

The manufacturer of the trailer has certified its compliance with all applicable Federal motor vehicle safety standards, including the conspicuity treatment location requirements of Standard No. 108. Paragraph S5.7.1.4.1(a) specifies that the material b e located "as close to the extreme edges as practicable." The relocation you contemplate would place the material where it is not as close to the extreme edges of the trailer as it originally was. This would create a noncompliance with Standard No. 108 .

Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(20(A)) (the Act) prohibits any manufacturer, dealer, distributor, or motor vehicle repair business from knowingly rendering inoperative, in whole or in part, any device or element of design installed in accordance with a Federal motor vehicle safety standard. The prohibition, however, does not apply to the vehicle owner. This means that Leprino Foods and its employees are not themselves prohibited by the Act f rom modifying your trailers to the configuration depicted in Photo #2. It does mean that a "manufacturer, dealer, distributor, or motor vehicle repair business" cannot perform this work for you.

We surmise that your trailers are subject to the jurisdiction of the FHWA when they are operated in interstate commerce. FHWA regulations require your trailer to be equipped to conform to Standard No. 108. Thus, if you modify your trailers so that they no longer conform to the rear location requirements of

Standard No. 108, you would be in violation of the regulations of that agency. This is to advise you that the FHWA has concurred in this interpretation to you.

Either mounting height location is permitted. Originally, Standard No. 108 did specify a mounting height for rear conspicuity material that was "as close as practicable to 1.25 meters above the road surface." However, the agency amended this paragraph on October 6, 1993, to adopt a height range of "as close as practicable to not less than 375 mm and not more than 1525 mm above the road surface." This is the equivalent of 15 to 60 inches above the road surface. Therefore, the mounting heights of 46 an d 56 inches shown in your two photos is in accordance with the revised requirement.

Finally, we note your comment that the diagram in the Federal Register "failed to consider the bumper bar area and the light assemblies that are actually on a van." The requirements that must be adhered to are found in the text of Standard No. 108; Figu re 30 is meant only as a general guide as to the placement of the conspicuity material. Obviously, it cannot depict the exact rear configuration of all van trailers.

ID: nht94-2.39

TYPE: Interpretation-NHTSA

DATE: April 14, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Thomas D. Turner -- Manager, Engineering Services, Blue Bird Body Company

TITLE: None

ATTACHMT: Attached to letter dated 1/6/94 from Thomas D. Turner to John Womack (OCC 9549); Also attached to letter dated 3/9/77 from Frank A. Berndt to W.G. Milby (Std. 217)

TEXT:

This responds to your letter of January 6, 1994, asking several questions concerning a recent amendment to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413; November 2, 1992). Our response to each of your questions fol lows.

1. Your first question requested confirmation that a left side emergency exit door required by S5.2.3.1(a)(2)(i) would meet the location requirements of S5.2.3.1(a)(2)(i) if it is located in the center one-half of the passenger compartment.

Your question concerns the first required additional emergency exit installed on a bus with a rear emergency exit door. Section S5.2.3.2(a)(2) requires this exit to be a side emergency exit door "located on the left side of the bus and as near as practi cable to the midpoint of the passenger compartment." Locating the door or the 12-inch required aisle opening for the door in the center one-half of the passenger compartment would not ensure compliance with this requirement. This is because it may be p ossible to locate a door in the center one-half without locating the exit "as near as practicable to the midpoint of the passenger compartment." In determining the permissible location for this exit, you should determine where the exit would be located if it was located at the midpoint of the passenger compartment. If it is not practicable to locate the exit there, you should move the door only as far as necessary for a practicable location.

2. Your second question requested confirmation that there are no fore and aft location requirements for side emergency exit doors other than the requirements for a left side emergency exit door required by S5.2.3.1(a)(2) (i).

You are correct. Except for a left side emergency exit door installed as the first additional emergency exit on a bus with a rear emergency door, the only location requirements for side emergency exit doors concern the side of the bus on which the exit must be located. I have attached for your information an appendix which lists all the location requirements for additional emergency exits.

3. Your third question requested confirmation that all side emergency exit doors, including any voluntarily installed, are required to comply with the requirements of the new final rule, including the seat placement requirements in S5.4.2.1( b).

You are correct. Your letter referred to a March 9, 1977 interpretation that voluntarily installed side emergency exit doors were not required to meet the school bus requirements, but were required to meet the non-school bus requirements. Previously, t he school bus emergency exit door requirements in Standard No. 217 referred to "the emergency door." At that time school buses were required to have either one rear emergency exit door or one side emergency exit door and one rear push-out window. Thus, any school bus was required to have only one emergency exit door. The reference to "the emergency door" was to the required door.

In the recent amendments to Standard No. 217, some of the performance requirements for emergency exits apply to "each" emergency exit. See, for example, S5.4.2.1(b). This change in the language extends these requirements to any emergency exit door in a school bus. Other requirements apply to "required" emergency exits. See, for example, S5.5.3(c). These requirements do not apply to voluntarily installed emergency exits.

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

APPENDIX Emergency Exit Location Requirements In the March 15, 1991, notice of proposed rulemaking to amend Standard No. 217, Bus Emergency Exits and Window Retention and Release, NHTSA proposed very specific location requirements for emergency exits in school buses (56 FR 11153). The agency receiv ed comments that many of these locations were not possible or practicable. In response to these comments, the agency concluded that the final rule should include only general requirements for the required exits (57 FR 49413; November 2, 1992). Therefor e, the only location requirements for additional emergency exits (1) included in the final rule were:

o For a bus with a rear emergency exit door, the first additional emergency exit must be an emergency exit door on the left side of the bus and as near as practicable to the midpoint of the passenger compartment (S5.2.3.2(a)(2)).

o For a bus with a side emergency exit door and a rear push-out window, the first additional emergency exit must be an emergency exit door on the right side of the bus (S5.2.3.2(a)(3)).

o If additional emergency exit doors are installed, they must be alternated between the right and left sides of the bus (S5.2.3.2(a)(2) and (3)).

o No two emergency exit doors may be located in the same post and roof bow panel space (S5.2.3.2(a)(4)).

o If one emergency roof exit is installed, it must be located as near as practicable to the mid-point of the passenger compartment (S5.2.3.2(b)(2)).

o If two emergency roof exits are installed, they must be located as near as practicable to a point equidistant from the midpoints of the passenger compartment and either the front or rear of the passenger compartment (S5.2.3.2(b)(3)).

o If three or more emergency roof exits are installed, the space between each exit shall, to the extent possible, be the same or equal to the space between the front (or rear) limit of the passenger compartment and the front (or rear) ro of exit (S5.2.3.2(b)(4)).

o Emergency roof exits must be installed so that their longitudinal centerline coincides with the longitudinal centerline of the bus, except that a roof exit may be offset a distance equal to the distance another roof exit is offset in the opposite direction (S5.2.3.2(b)(5) and (6)).

o Emergency window exits must be evenly divided between the right and left sides of the bus (S5.2.3.2(c)).

(1) The November 2 final rule requires all school buses to have either a rear emergency exit door or a side emergency exit door and a rear push-out window. The rule also requires "additional" emergency exits on buses of specified passenger capacities. " Additional" emergency exits, as the term is used in this appendix, refers to emergency exits other than the rear emergency exit door and side emergency exit door/rear push-out window which Standard No. 217 requires of all school buses.

ID: nht94-2.4

TYPE: Interpretation-NHTSA

DATE: March 29, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Harry C. Gough, P.E. -- Automotive Engineering Professional Specialist, State of Connecticut, Department of Motor Vehicles

TITLE: None

ATTACHMT: Attached to letter dated 12/2/93 from Harry C. Gough to NHTSA Chief Counsel (OCC 9398)

TEXT:

This is in reply to your letter of December 2, 1993, with respect to the term "alternately flashing" as it applies under Safety Standard No. 108 to school bus lamps. You ask for our opinion because a manufacturer of strobe lighting has supplied document ation indicating that the system complies with Standard No. 108.

According to your letter, in this system, the lamp on one side of the school bus (front and rear) "flashes on and off four times in a 255 millisecond period and then stays off for 745 milliseconds, then the lamp on the opposite side of the bus repeats th e aforementioned pattern." You inquire as to whether "alternately flashing" refers to this pattern, "or do the four distinct on/off cycles on each side of the school bus defeat the intent of the term alternating."

As you know, paragraph S5.1.4 of Standard No. 108 incorporates by reference SAE Standard J887, School Bus Red Signal Lamps, July 1964, which requires that school bus warning lamp systems "flash alternately." We believe that the light emanating from a st robe lamp that flashes four times in 0.255 second will be perceived as a single flash of varying intensity and not as four separate flashes, and that when this is followed by an identical pattern on the other side of the bus, the system is one that is al ternately flashing within the meaning of Standard No. 108.

Further, under this interpretation, the flash rate meets SAE J887's specification of 60-120 flashes a minute. Unlike other SAE materials incorporated by reference relating to signal lamps (e.g., J1133 School Bus Stop Arms in Standard No. 131 School Bus Pedestrian Safety Devices and J590b Automotive Turn Signal Flashers in Standard No. 108), J887 contains no "percent current 'on' time" requirements.

I hope that this answers your question.