ID: 16120.ztv

Mr. Scott Patten
Government Relations Coordinator
Kawasaki Motors Corp., U.S.A.
P.O. Box 25252
Santa Ana, CA 92799-5252

Dear Mr. Patten:

This is in reply to your letter of September 19, 1997, requesting an interpretation of Federal Motor Vehicle Safety Standard No. 108 as it pertains to motorcycle headlamps.

You have asked whether the shape of the outer lens of a motorcycle headlamp must be symmetrical in a headlamp design in which "the effective area of the reflector is symmetrical." The bulb, reflector, and lens are centered on the vertical centerline of the motorcycle. You believe that an asymmetrical outer headlamp lens is permissible as it is not specifically prohibited. You have also cited in support a letter from the NHTSA Chief Counsel dated January 12, 1987, to Stanley Electric. Co. stating that "the effective area of the reflector is used as the reference for headlamp location, rather than the outer edge of the headlamp lens."

We confirm your belief that an asymmetrtrical outer lens for a motorcycle headlamp is permissible under Standard No. 108. Table IV requires a motorcycle with a single headlamp to have the lamp located on the vertical centerline of the vehicle. As long as the bulb, reflector, and lens are centered on the vertical centerline, as you have indicated, the headlamp outer lens need not be the conventional circular or rectangular shape.

If you have any questions, you may refer them to Taylor Vinson of this Office (202-366-5263).

Sincerely,
John Womack
Acting Chief Counsel
ref:108
d.10/20/97

ID: 16136.ztv

Mr. Richard Rawlins
Triumph Homologation
Triumph Designs, Ltd.
Dodwells Bridge Industrial Estate
Jacknell Road
Hinckley, Leicestershire
LE10 3BS
England

Dear Mr. Rawlins:

This is in reply to your fax of September 24, 1997, to Luke Loy of this agency, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. For future reference, the Office of Chief Counsel is the appropriate office to which you should address requests for interpretations of the Federal motor vehicle safety standards.

You have asked whether rear side reflex reflectors on motorcycles must be mounted parallel to the vehicle's longitudinal centerline, or whether it is permissible to locate them approximately 9 degrees offset from the centerline.

Under Standard No. 108, lighting equipment is photometrically tested in the laboratory but must comply when installed on a motor vehicle. Thus, a reflex reflector should be mounted on the goniometer in the position in which it will be installed on a motor vehicle as well as being mounted in conformance with the specifications of SAE Standard J594f "Reflex Reflectors" January 1977, incorporated by reference in Standard No. 108. If the reflector meets the photometric requirements of SAE J594f when it is approximately 9 degrees offset from a line representing the motorcycle longitudinal centerline, then it would be permissible to mount it in an identical offset fashion on the motorcycle itself.

If you have any questions you may refer them to Taylor Vinson of this Office.

Sincerely,
John Womack
Acting Chief Counsel
ref:108
d.10/30/97

ID: 16190.ogm

Mr. Cesar Robles Gonzales
#10282-016
USP Allenwood
P.O. Box 3000
White Deer, PA 17887

Dear Mr. Gonzales:

This is in response to your request regarding seat belts for buses. Specifically, you are interested in seat belt requirements for charter and other buses operated by private bus lines.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized under Title 49, Chapter 301 of the U.S. Code to issue Federal motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles and new items of motor vehicle equipment. Chapter 301 prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment item is in conformity with all applicable safety standards.

Large buses, those with a gross vehicle weight rating (GVWR)over 10,000 pounds, are not required to have seat belts for occupants other than the driver. Standard No. 208, Occupant Crash Protection (49 CFR 571.208) sets forth the crash protection requirements applicable to most vehicle types. Section S4.4 of that standard sets forth the requirements applicable to large buses other than school buses. That section requires large buses to have either a complete automatic protection system for the bus driver's seating position, or a seat belt assembly that conforms with Standard No. 209 at the driver's seating position. Standard No. 208 does not specify any requirements for either an automatic protection system or seat belt assemblies to be installed at any other seating positions in large buses.

I hope this information is helpful.

Sincerely,
John Womack
Acting Chief Counsel
ref:208
d.12/11/97

ID: 16206.drn

Mr. George J. Aumond
President
Intec Industries, Inc.
1025 S. Linwood Ave.
Santa Ana, CA 92705

Dear Mr. Aumond:

This responds to your request for an interpretation whether your company must assign new vehicle identification numbers (VINs) to used trailer chassis, under the facts described in your letter. If the trailers are modified in accordance with NHTSA's regulations on combining new and used components in trailer manufacture, the trailers would be considered used and the VIN assigned to each trailer may be retained.

Your letter states that Intec Industries is in the process of redesigning 40-foot shipping container chassis to "accommodate new laws pertaining to distribution of weight on bridges." You describe the changes as follows:

The modification is accomplished by modifying an existing 40' straight frame chassis, to accommodate one 20' container, with a 48,000 pound load, or, two empty 20' containers, or one 40' or 45' container with 48,000 pound loads. When completed, only the rear 10' of the 40' frame is not used. The compressed length of finished unit is 30'-0". All braking systems, wheels, tires, accumulation tanks, and fifth wheel components, are essentially left intact, and are incorporated into the new design.

In a telephone conversation with Dorothy Nakama of my staff, you stated that if possible, your company would like to retain the assigned VIN on the modified trailers. You further stated that after the changes are made, the gross vehicle weight rating and the gross axle weight ratings of each trailer chassis will remain the same. The distance between the wheels (on the same side of the vehicle) will be adjusted, so that the trailer chassis' load distribution will be in line with new bridge weight requirements.

NHTSA's regulations at 49 CFR 571.7(f) Combining new and used components in trailer manufacture apply to your company's trailer modifications. That regulation provides:

When new materials are used in the assembly of a trailer, the trailer will be considered newly manufactured for purposes of [the Federal Motor Vehicle Safety Standards] unless, at the minimum, the trailer running gear assembly (axle(s), wheels, braking and suspension) is not new, and was taken from an existing trailer -

(1) Whose identity is continued in the reassembled vehicle with respect to the Vehicle Identification Number; and

(2) That is owned or leased by the user of the reassembled vehicle.

Thus, if the trailers are modified under the conditions described in Section 571.7(f), the trailers would be considered used, and Intec Industries may continue to use the assigned VINs on the modified trailers.

Please note that in the modification process, your company must ensure that the certification labels (assigned pursuant to 49 CFR Part 567 Certification) remain on the trailers. Additionally, in order to avoid a violation of 49 U.S.C. 30112(b), when modifying the trailers, your company must not "knowingly make inoperative any part of a device or element of design installed on or in [those vehicles] in compliance with an applicable motor vehicle safety standard..."

I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama at this address or at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
ref:565#567
d.2/26/98

ID: 16242.drn

Ms. Kay Howeth
Executive Director
St. Michaels Housing Authority
P. O. Box 296
St. Michaels, MD 21663

Dear Ms. Howeth:

This responds to your October 7, 1997, request for an opinion whether St. Michaels Housing Authority must provide school bus transportation for your children in a drug awareness program. The answer to your question is determined by Maryland State law.

Our statute at 49 U.S.C. 30112(a) requires any person selling or leasing a new vehicle to sell or lease a vehicle that meets all applicable Federal motor vehicle safety standards. Accordingly, persons selling or leasing a new "school bus" must sell or lease a vehicle that meets the safety standards applicable to school buses. Under 49 U.S.C. 30101, et seq., a "school bus" is any vehicle that is designed for carrying 11 or more persons and which is likely to be "used significantly" to transport "preprimary, primary, and secondary" students to or from school or related events. 49 U.S.C. 30125.

Since the National Highway Traffic Safety Administration (NHTSA) does not consider a drug awareness program to be a "school," we would not require that a dealership selling a new vehicle to your Housing Authority sell a school bus. However, each State has authority to regulate the use of vehicles within the State, and Maryland law may specify the type of vehicle your Housing Authority must use to transport the children. You may wish to contact the Maryland State department of motor vehicles to learn whether there are any State requirements applicable to vehicles used to transport children in drug awareness programs.

For your information, I am also enclosing a copy of NHTSA's publication, "Frequently Asked Questions About Federal School Bus Safety Requirements."

I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

John Womack
Acting Chief Counsel

Enclosures

ref:VSA#571
d.11/5/97

ID: 16250.ztv

Mr. Gene Trobaugh
President
Whizzer Motorbike Company
1915 Orangewood Avenue, Suite 200
Orange, CA 92868-2047

Dear Mr. Trobaugh:

This is in reply to your Petition to the Administrator dated October 2, 1997, on behalf of a "motor-assisted bicycle."

You request "relief from meeting DOT regulations" for two reasons. The "motor-assisted bicycle" requires human power to start from a static position. It will not exceed 25 miles per hour. In addition, it is designed to accommodate only one person and has less than 2 horsepower.

To respond to your petition, we must first decide whether the Whizzer is a "motor vehicle" and required to comply with the regulations from which you seek to be excused. Under our safety law, a "motor vehicle" is a vehicle driven by mechanical power and manufactured primarily for use on the public streets. With respect to bicycles with motors, we use the term "power-assist" to refer to a vehicle that cannot be driven by the motor alone but which requires muscular input at all times when in motion, assisted when needed by the engine. We do not consider this type of vehicle to be a "motor vehicle" subject to our regulations. If this correctly describes the Whizzer, then your petition is moot. However, if the Whizzer is capable of being propelled by the engine alone with no muscular power required when the engine is engaged, then the Whizzer would be a "motor vehicle", specifically a "motor driven cycle."

The Whizzer's speed capability of 25 miles per hour is somewhat greater than is ordinary for operation by muscular power alone.

Assuming that the Whizzer is a motor vehicle, we cannot by this letter provide blanket relief from DOT regulations. We therefore view your petition as one for rulemaking that would exclude the Whizzer and other vehicles in its class from DOT requirements. The agency's Office of Safety Performance Standards has the responsibility of evaluating and responding to petitions for rulemaking within 120 days of their submission. Accordingly, I am providing them with a copy of your petition for such further action as that Office deems appropriate.

Alternatively, you request relief "from meeting DOT lighting requirements." The reasons for this request is that the Whizzer is best suited for daytime operation and that you do not want to encourage operation at night. In addition, due to its nature, the Whizzer is likely to be used only for casual, recreational riding.

There are two ways to proceed with your petition. We can treat it as a petition for rulemaking to be considered with your primary petition for relief from compliance with all DOT regulations. That is the simplest way to proceed, and we shall do so unless instructed by you to the contrary.

The second way is to treat it as a petition for temporary exemption from Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment. However, your petition does not contain the information required by the agency's regulation 49 CFR Part 555. There are four bases on which temporary exemptions are granted. If immediate compliance would cause substantial economic hardship to a manufacturer that has tried in good faith to comply with Standard No. 108, an exemption of up to three years may be granted, provided that the total vehicle production of the manufacturer in the year preceding the filing of its application did not exceed 10,000 units. If an exemption from Standard No. 108 would facilitate the development and field evaluation of a low-emission vehicle or one with innovative safety features and would not unduly degrade the safety level of the vehicle, or if, in the absence of an exemption from Standard No. 108, a manufacturer would be unable to sell a vehicle whose overall level of safety is equal to or exceeds that of a non-exempted vehicle, an exemption of up to two years may be granted which would apply to not more than 2,500 vehicles a year. The exemption process takes three to four months after a petition is received that meets the requirements of Part 555.

If you wish further information on this exemption procedure, you may telephone Taylor Vinson of this Office (202-366-5263). Further correspondence on petitions for rulemaking should be directed to L. Robert Shelton, Associate Administrator for Safety Performance Standards.

Sincerely,

John Womack
Acting Chief Counsel

ref:571
d.11/17/97

ID: 16262-1.pja

Mr. Dale Dierks
Engineering Manager
Trail-Eze
1909 S. Rowley
Mitchell, SD 57301

Dear Mr. Dierks:

This responds to your letter requesting an interpretation of whether several different trailers your company manufactures would be excluded from the National Highway Traffic Safety Administration's (NHTSA's) rear impact protection (underride guard) regulations. In a May 14, 1998, telephone conversation with Paul Atelsek, one of our attorneys, you explained that you had changed the designs of your trailer line so that you are confident that all but one of the trailers now comply with the rule. You asked Mr. Atelsek to address only the Model DHT Series Hydraulic Tail trailers. As explained below, this trailer is an excluded low chassis vehicle, to which our underride guard regulations do not apply.

These trailers are essentially a flatbed design, with an eight foot long, full width tail section extending rearward behind the rear tires. The rear edge of the tail section can be raised or lowered using hydraulic cylinders located beneath the front part of the tail. The tail section tilts down to permit loading of wheeled vehicles. At the rear of the tail section is a four foot long, full width approach plate. During loading, the approach plate extends farther rearward (12 feet total length from the front edge of the tail section) and downward, bridging the gap between the tail section and the ground. Its purpose is to allow construction equipment to transition across its triangular cross section from the ground up onto the bed without encountering the "bump" of the edge of the tailpiece.

During transit, this approach plate folds under the tail section and stows against the bottom of the tail section. You added further detail in a March 27, 1998, telephone conversation with Mr. Atelsek. Although the tail section can be tilted up and down, it is designed so that it can not be transported in any position other than the horizontal position, and that the tail section and the approach plate both lock into that position. In this position, you state that the combined rear surface of the tail section and the approach plate meets the configuration requirements our regulations. However, without counting the tucked-under approach plate, the lower rear of the tail section does not meet the configuration requirements because it is too far above the ground. The approach plate is attached by a large full-width piano-type hinge, fits into an indentation on the bottom of the tail section, and locks in place there during transit.

Federal Motor Vehicle Safety Standard No. 224, Rear impact protection, requires most trailers and semitrailers weighing over 10,000 pounds to be fitted at the rear with a rear impact (underride) guard meeting the requirements of Standard No. 223, Rear impact guards (49 CFR 571.223 and 571.224, published on January 24, 1996, at 61 FR 2004). However, certain kinds of vehicles are excluded. The only excluded category that is relevant for the purposes of this letter is low chassis vehicles.

Low chassis vehicles are defined in S4 of Standard No. 224 as "a trailer or semitrailer having a chassis that extends behind the rearmost point of the rearmost tires and a lower rear surface that meets the configuration requirements of S5.1.1 through 5.1.3 of this section." In other words, the chassis itself must satisfy the configuration requirements applicable to a guard when the vehicle is outfitted for transit. The only part of your vehicle that may meet these configuration requirements is the rear edge of the folded approach plate itself, so the question becomes whether the approach plate is considered to be part of the "chassis" of the vehicle. Chassis is defined in S4 as "the load supporting frame structure of a motor vehicle." There are two elements to this definition that must be satisfied: "load supporting" and "frame structure."

To be considered "load supporting," the frame structure has to support load when the trailer is performing its function. Generally, this means that the structure would have to contribute to supporting the cargo load when the trailer is in transit.

To be considered part of the frame structure, a structural member must be either an integral part of the overall frame structure, or be connected with other frame structural members in a way that is necessary to the structural integrity of the trailer. One factor the agency considers in deciding whether a structural member is part of the frame is its size and strength. Frame structural components often are the major structures defining the shape of the trailer. Although frame structure is not limited to the largest frame components (i.e., the frame rails for most trailers), generally frame components are substantial and have strength similar to other frame components. Moveable components may "lock" into the frame structure sufficiently that they are integral with other frame members-in this situation NHTSA may consider the combined components to be one frame unit. However, the agency also looks at the purpose and function of the structural member in supporting the trailer and its load.

Applying these principles to your approach plate, we conclude that it is part of the chassis. The folded approach plate conforms with the outline of the underside of the trailer bed, maintaining a constant bed thickness and helping to define the outline of the bed. Your approach plate is hinged along the entire rear of the trailer and, when folded, locks at its forward edge into a place fitted for it on the underside of the chassis. NHTSA considers the approach plate on your trailer to be "locked" into the frame of the vehicle sufficiently that it is considered integral with it, as one unit, and therefore a part of the frame structure. By contributing to the structural integrity of these frame members, NHTSA considers the approach plate to be supporting load. Therefore, the approach plate is part of the chassis, and the trailer is a low chassis vehicle, excluded from the underride guard requirements.

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

Sincerely,
John Womack
Acting Chief Counsel
ref:224
d.5/22/98

ID: 16264.ogm

Mr. Gary Gawura
Program Manager
Track Corporation
1091 Centre Drive
Suite 210
Auburn Hills, MI 48236

Dear Mr. Gawura:

This responds to your letter concerning Standard No. 207, Seating Systems and Standard No. 210, Seat Belt Assembly Anchorages as they apply to a seat design having an upper seat belt anchorage integrated into the seat and lower seat belt anchorages integrated into the adjuster. I apologize for the delay in responding.

You ask several questions regarding the proper test procedures for designs such as yours where the seat belt assembly anchorages are integrated into the seat rather than attached to the vehicle itself. Your letter contains a description and diagram of the current test procedure used by your company to test seats and seat belt anchorages. You indicate that in order to test the belt anchorages, a 3000 pound load is applied to the shoulder and the lap belts as specified in S5.2 of Standard No. 210. You also indicate that a "C.G. force at 20 times the weight of the seat is applied to the seatback and another C.G. force a t 20 times the weight of the pedestal is applied to the pedestal. These loads are held for ten (10) seconds."

The first question you ask is whether it is necessary, under your current test procedure as described above, to apply a load to the pedestal because, as a seat manufacturer, you are not certifying the attachment of the seat to the vehicle.

Depending on the standard involved, Federal motor vehicle safety standards may apply to a manufacturer of motor vehicle equipment, to a vehicle manufacturer or to both. S2 of Standard No. 209 specifies that the standard applies "to passenger cars, multipurpose passenger vehicles, trucks and buses. Therefore, the manufacturer of the vehicle is responsible for ensuring that the product meets the requirements of Standard No. 209. Given the fact that Standard No. 209 requires that the seat be installed in a vehicle when compliance testing is performed, it may not be possible for your company to perform such testing.

If, as your diagram indicates, the load being applied to the pedestal portion of the seat is intended to be the load which must be applied to cg₂, the center of gravity of the portion of the seat below the adjuster, as required by S5.1.1(c), a vehicle manufacturer would be required to ensure that the seat assembly met those requirements. As a seat manufacturer, your company is not obligated to do so.

You also ask that the agency comment on a proposed test procedure which your company believes would be more appropriate for testing seats with integrated seat belt anchorages for both lap and shoulder belts. As depicted in a diagram in your letter, this test applies a 3000 pound load to the lap and shoulder belt anchorages and a 20g load to the seat back and the seat "pan."

Your diagram refers to the load applied to the seat back as the upper CG load and the load applied to the seat "pan" as the lower CG load. As the seat "pan" in the seat depicted in your diagram is above the adjuster, the lower CG load shown in this diagram is presumably not the actual lower CG load but rather represents your nomenclature for the load that would be applied to cg₂ under S5.1.1(c).

The test that your company proposes clearly does not meet the current requirements of Standard No. 207. It is not clear from your letter if this test is performed with the seat attached to the vehicle. If it is not, the test would obviously not test the strength of the attachment of the seat to the vehicle. Secondly, it is not possible to evaluate your proposed test from the information contained in your letter. However, it appears that the test you propose would place greater loads on the seat frame and adjuster than the current requirements of S5.1.

Finally, you ask for a complete set of standards and rulings related to the testing of integrated adjusters and seats. The requirements for seat belt anchorages are found in S5 of Standard No. 210. As you are aware, the requirements for seats are found in S5.1 of Standard No. 207. Copies of these standards are enclosed as well as the accompanying test procedures.

NHTSA is currently studying possible changes to Standard No. 207 as well as an October 28, 1997 petition for rulemaking submitted by Bornemann Products, Inc. requesting that the agency initiate rulemaking to modify Standard No. 207 in regard to the testing of integrated seats.

I hope that this is responsive to your inquiry.

If you have any questions, please contact Otto Matheke of my staff at (202) 366-5253.

Sincerely,
John Womack
Acting Chief Counsel
ref:207
d.4/1/98

ID: 16281-1.pja

Mr. Craig Heider
Manager
Jet Co.
1303 North 13^th Street
Humboldt, IA 50548

Dear Mr. Heider:

This responds to your letter requesting an interpretation of whether three different trailers your company manufactures would be excluded from the National Highway Traffic Safety Administration's (NHTSA's) rear impact protection (underride guard) regulations. You ask if a grain trailer with fixed rear axles and a rearmost surface of the rearmost tires within 305 mm of the rear extremity of the trailer is excluded as a wheels back vehicle. You also ask if a flatbed/dropdeck trailer with a beavertail and a composite dropdeck trailer are excluded as a low chassis vehicle. On the basis of the information you supplied and certain assumptions discussed below, it appears that all three of these vehicles are excluded.

Federal Motor Vehicle Safety Standard No. 224, Rear impact protection, requires most trailers and semitrailers weighing over 10,000 pounds to be fitted at the rear with a rear impact (underride) guard meeting the requirements of Standard No. 223, Rear impact guards (49 CFR 571.223 and 571.224, published on January 24, 1996 at 61 FR 2004). However, certain kinds of vehicles are excluded. The only excluded categories that are relevant for the purposes of this letter are wheels back vehicles and low chassis vehicles.

Wheels-back vehicles, excluded by S3 of FMVSS No. 224, are defined in S4 as a "trailer or semitrailer whose rearmost axle is permanently fixed and is located such that the rearmost surface of [the tire] on that axle is not more than 305 mm forward of the transverse vertical plane tangent to the rear extremity of the vehicle."

You state in your letter that the rear axles of your grain trailer meet both of these criteria. The copy of a photograph you enclosed of the trailer appears consistent with your description, although no dimensions are given. Accepting your assertion that the rear surface of the tires on the fixed axle are within 305 mm of the rear extremity, NHTSA concludes that the vehicle is excluded.

Your flatbed/dropdeck trailer, labeled "53' X 102" Steel Dropdeck" in the literature you enclosed with the letter, is essentially a flatbed design, with a five foot dropdeck (also called a "beavertail") extension angling downward from the rear of the flat portion of the bed. There are two loading ramps that bridge the distance from the lower rear of the beavertail to the ground during loading, allowing vehicles to be driven onto the flatbed. During transit, the loading ramps, which are located on the left and right sides of the beavertail section, pivot on a hinge at the rear of the beavertail and flip over and lie on top of the beavertail section. The literature you enclosed states "ramps make the beavertail flat for more loading area." By this, we assume you mean that the bottom surface of the loading ramps, when sitting on top of the beavertail, forms an extension of the flat portion of the trailer during transit, and that the extension can support cargo load. In a conversation with Mr. Paul Atelsek of my staff, you clarified that the rear surface of the beavertail extends from one side of the trailer to the other and its lower surface is less than 22 inches above the ground.

Low chassis vehicles are defined in S4 of Standard No. 224 as "a trailer or semitrailer having a chassis that extends behind the rearmost point of the rearmost tires and a lower rear surface that meets the configuration requirements of S5.1.1 through 5.1.3 of this section." In other words, the chassis itself must satisfy the configuration requirements applicable to a guard when the vehicle is outfitted for transit. The only part of your vehicle that may meet these configuration requirements is the rear edge of the beavertail itself, so the question becomes whether the beavertail is considered to be part of the "chassis" of the vehicle. Chassis is defined in S4 as "the load supporting frame structure of a motor vehicle." There are two elements to this definition that must be satisfied: "load supporting" and "frame structure."

To be considered "load supporting," the frame structure has to support load when the trailer is performing its function. Generally, this means that the structure would have to contribute to supporting the cargo load when the trailer is in transit.

To be considered part of the frame structure, a structural member must be either an integral part of the overall frame structure, or be connected with other frame structural members in a way that is necessary to the structural integrity of the trailer. One factor the agency considers in deciding whether a structural member is part of the frame is its size and strength. Frame structural components often are the major structures defining the shape of the trailer. Although frame structure is not limited to the largest frame components (i.e., the frame rails for most trailers), generally frame components are substantial and have strength similar to other frame components. Moveable components may "lock" into the frame structure sufficiently that they are integral with other frame members-in this situation NHTSA may consider the combined components to be one frame unit. However, the agency also looks at the purpose and function of the structural member in supporting the trailer and its load.

Applying these principles to your beavertail, the agency concludes that it is part of the chassis. The beavertail helps to define the shape of the trailer. It is of a similar size and strength to the other frame components. Your beavertail is attached to the rest of your chassis sufficiently that it is considered integral with it, as one unit, a part of the frame structure. In addition, the beavertail meets the "load supporting" aspect of the chassis definition because it can support cargo load. Therefore, the beavertail is part of the chassis, and the trailer is a low chassis vehicle, excluded from the underride guard requirements..

Your third trailer type, labeled "53' X 102" Composite Dropdeck" is a straight flatbed trailer with the frame rails in the rear of the trailer extending 10 feet behind the rear wheels. The vertical face of the chassis at the rear is 13 inches from top to bottom, and although it is not apparent from your line drawing, we assume that this depth dimension is constant across the back of the trailer. The distance from the ground to the bottom of the chassis is 21 inches when the trailer is unloaded. Because the rear face is at least 4 inches high, extends outward to within 4 inches of the trailer side extremities, and is no more than 22 inches from the ground when the trailer is unloaded, it meets the configurational requirements of S5.1.1 to S5.1.3. The rear face of the trailer connecting to the frame rails is considered to be frame structure. Assuming that the rear of the bed can support load, this structure is part of the chassis. Since this structure meets the configurational requirements of the rule, this vehicle is an excluded low chassis vehicle.

You also asked about the labeling requirements if a vehicle falls in an excluded category. There are no requirements for excluded vehicles in our regulations. If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
ref:224
d.5/22/98

ID: 16305.ztv

Mr. Vann H. Wilber
Director
Vehicle Safety & International Department
American Automobile Manufacturers Association
1401 H Street, N.W.
Washington, D.C. 20005

Re: Definition of Optical Axis of a Headlamp

Dear Mr. Wilber:

This is in reply to the letter of October 23, 1997, that you and Jeff Erion wrote pointing out a possible inconsistency in the interpretation we provided Steve Law on June 16, 1997, and "the conclusions of the Regulatory Negotiation (Reg Neg) on this subject." Mr. Law had asked whether certain marking configurations met the requirements of paragraph S7.8.5.3(f)(1) of Standard No. 108.

In brief, we advised Mr. Law that markings at the center of each of the four sides of a rectangular headlamp were insufficient to denote the optical axis, which runs directly through the center of the headlamp at 90 degrees to the lens face. However, the final rule and its preamble are silent as to the type of mark that must denote the optical axis. You say that the Reg Neg Committee determined that "marks on the periphery of the lens which could be converged to the center of the lens" would be acceptable, and that Mr. Law's Option C meets this requirement.

The marks on Option C are located at the center of each of the four sides, oriented at 90 degrees from the side. If lines are drawn between opposing sides, they will converge at the center of the headlamp, at the optical axis. We agree that this is a sufficient indication of the optical axis to meet the requirements of paragraph S7.8.5.3(f)(1), and that Mr. Law's Option C is acceptable. This reverses our opinion on Option C that we provided Mr. Law on June 16, 1997.

However, the marks on Option B, located on each side, are parallel to the side. This means that lines drawn between opposing sides will not necessarily intersect on the optical axis unless they are drawn from the center of each line, which is not marked. Option B thus remains unacceptable because lines cannot be converged to the center of the lens from any point on the marks located at the sides of the headlamp.

We are providing Mr. Law and Mr. Erion with a copy of this letter.

Sincerely,
John Womack
Acting Chief Counsel
cc: Steve Law
Jeff Erion
d.12/22/97
ref:108