Mr. Kenneth D. MacArthur
Farm Bed Manufacturing, Inc.
Box A, Eisenman Road
Boise, Idaho 83705

Dear Mr. MacArthur:

This responds to your letter requesting that your vehicle be excluded from the National Highway Traffic Safety Administration's (NHTSA's) rear impact protection (underride guard) regulations. I apologize for the delay in responding. As explained below, your vehicle is not excluded from the regulation.

Your company manufactures self-unloading bulk trailers that have small conveyer belts at the lower rear of the trailer to unload potatoes and other agricultural products. The rear shaft mount for the conveyor belt protrudes 24 inches from the rear of the trailer in order to drop the potatoes onto another conveyer belt (called a piler) that resides at the unloading site. You believe that the small conveyor belt should be considered "work performing equipment," thus making the trailer a "special purpose vehicle" that is excluded from the requirement to have an underride guard.

After January 1998, Federal Motor Vehicle Safety Standard (FMVSS) No. 224, Rear impact protection, will require most trailers and semitrailers weighing over 10,000 pounds to be fitted at the rear with an underride guard. An excluded category of vehicle is special purpose vehicles. A special purpose vehicle is defined in S4 of FMVSS No. 224 as "a trailer or semitrailer having work-performing equipment . . . that, while the vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear underride guard . . . ." (Emphasis added.)

Your vehicle does not meet the definition of a special purpose vehicle. The small conveyor belt at no time passes through the area where the horizontal member of the underride guard would be located, and it certainly does not do so while the vehicle is in transit. Therefore, your trailers are not excluded from the standard as special purpose vehicles.

As you pointed out in your letter, NHTSA addressed this issue in the January 20, 1996 final rule on underride (61 FR 2004). The National Potato Council commented that an underride guard would impair the function of the conveyor, without explaining how. NHTSA responded that, if this were true, the vehicle would probably be a special purpose vehicle (61 FR at 2022). However, it now appears that the conveyor function would not be impaired in a manner that would exclude it under the rule as written (i.e., the conveyor does not reside in or move through the guard area while the vehicle is moving).

This letter merely applies the existing regulatory language to the question you posed, and does not constitute a judgment that your trailers could operate with a conventional underride guard in place. There may be engineering solutions that you have not yet explored that would meet the requirements of the standard without compromising the function of your vehicle.

If there are solutions that you would not be able to implement before the January 26, 1998 effective date of the rule, you can apply for a temporary exemption. Under one of our regulations (49 CFR Part 555), vehicle manufacturers may apply for a temporary exemption from the Federal motor vehicle safety standards. Under Sec. 555.6(a), a manufacturer whose yearly production is not more than 10,000 units may ask for an exemption of up to three years on the basis that compliance would cause it substantial economic hardship and that it has attempted in good faith to comply with the standard from which it has asked to be excused. I have enclosed a copy of Part 555 for your information. Please note that it takes three to four months from the date of submittal before a decision can be made on such an application because it has to be submitted for public comment. You may also submit a petition for rulemaking (see 49 CFR Part 552, copy enclosed) requesting that NHTSA amend the standard to exclude these vehicles.

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.

John Womack
Acting Chief Counsel