Mr. Jay Reese, Engineering Manager
Fontaine Specialized
P. O. Box 289
5398 U.S. Highway 11
Springville, AL 35146

Dear Mr. Reese:

This responds to your request for an interpretation of vehicle identification number (VIN) requirements for trailers. You wish to know whether a trailer, consisting of a gooseneck, a deck, a 2-axle (or 3-axle) bogie and two separate sets of an axle unit attached to tires, is one or several trailers.

As explained below, the answer depends on whether the bogie and axles are sold as one unit or separately. If sold with the gooseneck, deck, and bogie, the axle-tire unit is part of a trailer and would not have a separate VIN. If sold separately, each axle-tire unit is a trailer. Each trailer must have a distinct VIN and must meet the National Highway Traffic Safety Administration's (NHTSA) certification requirements.

Your letter stated that the axles with tires can separate from each other and from the bogies to form different trailer configurations. In a telephone conversation with Dorothy Nakama of my staff, you explained that the customer may first buy the trailer with the bogie only, and later buy one or both axle-tire units. Each axle-tire unit consists of a load bed, an axle, and tires. To lessen confusion, especially when the bogie is sold or used separately from each axle-tire unit, you wish to assign separate VINs to the bogie and each axle-tire unit.

Although you ask about VIN requirements (specified at 49 CFR Part 565 Vehicle Identification Number Requirements), please be aware that NHTSA's vehicle certification requirements, at 49 CFR part 567 Certification, also apply. The "VIN Data Plate" you refer to describes information required for the trailer's certification label, including the gross vehicle weight rating (GVWR) and gross axle weight rating (GAWR). In answering your questions, I will describe both your VIN and certification responsibilities.

Your letter raised the following hypothetical situations and posed questions based on the hypotheticals.

Hypothetical One: First, your customer purchases a trailer with a 2-axle bogie and two removable axle-tire units. You state that your "VIN Data Plate" includes four axles, the "entire length of the trailer" (by which I assume you include the length of the bogie plus two axles), GVWR (for 4 axles) and other required information.

1. Your first question is if the customer removes the third and fourth axles, so there are only "2-Axles on the ground, is the VIN still in compliance."

The answer is yes. The VIN requirement and certification requirements apply to a new vehicle. If you sell a new trailer with four axles, the VIN attributes and vehicle certification label must identify the trailer as having four axles and describe the appropriate GVWR and other information applicable to a new 4-axle trailer. For NHTSA's purposes, your customer's removing the two separate axles does not affect the VIN and certification label you place on the new 4-axle trailer.

Please note that since it reflects a trailer with four axles, the GVWR on the "VIN Data Plate" would no longer be accurate if the third and fourth axles are removed. However, if you sell a trailer with four axles, and the customer removes two axles, removing the axles would not result in a noncompliance with certification requirements.

2. The second question is, if only 3 axles are used (the bogie plus one axle) for a certain load, would the VIN still be in compliance?

The answer is the same as the answer to the question above. The VIN and certification requirements apply to a new vehicle. Your customer's removing a separate axle does not affect the VIN and certification label you place on the 4-axle trailer.

3. The third question is whether a VIN is required for "each individual removable axle."

The answer to this question depends on how the "individual removable axle" is sold. If the axle is sold as part of a trailer (i.e., with the gooseneck, deck and bogie), the VIN information and certification label on the trailer should reflect the fact that the individual axle is a part of the trailer. For example, the attribute describing vehicle length should include the length of the individual removable axle.

If sold separately, the axle-tire unit should have its own VIN and certification label. The reason is that in your case, "each individual removable axle" is a motor vehicle i.e., a trailer. Under NHTSA's statute, a motor vehicle is defined as: " a vehicle driven or drawn by mechanical power and manufactured primarily for use on public streets, roads, and highways, but does not include a vehicle operated only on a rail line." (49 U.S.C. 30102(a)(6)).

NHTSA defines a trailer as: "a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle." (49 CFR section 571.3)

Applying the above definitions, each axle-tire unit is a motor vehicle since it is drawn by mechanical power and includes tires that enable it to travel on the public roads. Each axle-tire unit is a trailer since it is designed to carry property and to be drawn by another vehicle. In the case of the axle-tire units, the "other vehicle" may be the bogie or another axle-tire unit.

Please note that 49 CFR 565.4(a) provides that "[e]ach vehicle manufactured in one stage shall have a VIN that is assigned by the manufacturer." Each motor vehicle must be assigned only one VIN. Therefore, if you assign a VIN to a 4-axle trailer (including two removable axles), you should not assign separate VINs to each axle-tire unit.

Hypothetical Two: In the second hypothetical situation, you state that your customer purchases a trailer with a 3-axle bogie plus one axle-tire unit, with an option to purchase an additional axle-tire unit later. Your certification label ("VIN Data Plate") consists of "4-Axles and GVWR for 4-Axles, and a secondary plate that comprises of 5-Axles and GVWR for 5-Axles." The VIN attributes note the entire length of the trailer for a 5-axle trailer and "all other required information."

Before I respond to your question, I note that if you sell a trailer with 4 axles, the trailer's VIN attributes (including trailer length), should be for a trailer with 4 axles. The certification label correctly provides information for a 4-axle trailer.

1. The first question is, if your customer purchases the fifth axle, will the VIN be in compliance, since the trailer that he bought includes information about vehicles with five axles.

Assuming the VIN reflects a trailer with four axles, whether your customer buys a fifth axle separately and installs it later, that installation has no effect on the original compliance of the trailer with NHTSA's regulations. If the fifth axle is sold separately as an axle-tire unit, it must meet applicable NHTSA requirements for trailers.

Please note that in the past, NHTSA has permitted manufacturers to include information on the certification label beyond that which Part 567 requires. In your case, extra information would include information concerning the addition of a fifth axle-tire unit to a trailer sold with 4 axles. Where NHTSA has acquiesced in this practice, the additional information (the information about the fifth axle-tire unit) has appeared after that required under section 567.4(g).

2. The second question is whether a separate VIN will be required for the fifth axle-tire unit.

As explained in the answer to question three under the first hypothetical situation, the answer is yes. If sold separately, the fifth axle-tire unit must have have its own VIN and certification label, since the fifth axle-tire unit would be considered a motor vehicle, specifically a trailer.

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


John Womack

Acting Chief Counsel