Interpretation ID: 77-3.17

TYPE: INTERPRETATION-NHTSA

DATE: 07/01/77

FROM: AUTHOR UNAVAILABLE; Joseph J. Levin Jr.; NHTSA

TO: Miller Trailers Inc.

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of May 6, 1977, concerning a vehicle manufacturer's responsibilities with regard to overloading.

You make reference to several recent interpretations from the National Highway Traffic Safety Administration (NHTSA) which stated that manufacturers must take reasonable steps to ensure that the vehicles they produce will not be overloaded by their users. Although we acknowledge that a manufacturer does not have direct control over the actual use of its vehicles, it does exercise indirect control over use through the vehicle's design.

The NHTSA has stated in the past that a vehicle's gross vehicle weight rating (GVWR) is determined by the sum of its unloaded vehicle weight, 150 pounds for each designated seating position, and its rated cargo load. It is the cargo load rating that is most relevant to the problem of overloading. The rated cargo load should represent the manufacturer's assessment of the vehicle's cargo-carrying capacity and the maximum load at which the vehicle may be safely operated. A manufacturer must consider the maximum load capacity of the vehicle when it designs its cargo-carrying portion. If this is not done, the rated cargo load, and thus the GVWR, may be meaningless since the vehicle may have a cargo-carrying chamber which, if filled, would cause the vehicle to exceed its stated weight ratings. An illustration of such a situation would be a tanker truck which exceeds its GVWR when the tank is filled with a type of material appropriate for carrying in that cargo area. If the manufacturer could reasonably have anticipated that such cargo would be carried in the tanker, yet rated the vehicle with a GVWR which was less than the vehicle's weight when fully loaded with that cargo, a safety-related defect for which the manufacturer is responsible may be considered to exist.

The NHTSA does not expect manufacturers to be omniscient when it comes to the use of the vehicles they produce. It does, however, expect the stated weight ratings to reflect the design of the vehicles and the uses to which they can reasonably be anticipated to be put. Where the manufacturer has reason to know the specific commodity intended to be carried in its vehicles and those vehicles have a totally enclosed cargo area, as with a tanker, the rated cargo load is relatively easy to determine.

A manufacturer's responsibility for any subsequent overloading of the vehicles it manufactures would be determined by the reasonableness of its GVWR's and gross axle weight ratings (GAWR), given the size and configuration of its vehicles and the types of loads which they could reasonably be expected to carry. In the case of flat beds (no enclosed cargo area) a manufacturer would obviously not be able to provide weight ratings sufficiently high to prevent overloading in all instances. The design of flat beds necessarily permits overloading since the cargo area is unrestricted. Thus if the weight ratings specified appear to have been arrived at by a good faith determination based upon the types of loads the manufacturer anticipates will be carried, its responsibility with regard to weight rating specifications will have been satisfied and no safety-related defect will be attributable to it.

SINCERELY,

SPECIAL PRODUCTS DIVISION MILLER TRAILERS, INC.

May 6, 1977

Frank Berndt Acting Chief Counsel National Highway Traffic Safety Administration

I have recently read with interest and concern several legal interpretations from NHTSA regarding GVW and GAW Ratings assigned by vehicle manufacturers and that relationship to the actual operation by the end user in which these ratings may or could be exceeded.

I'm sure you are well aware that general purpose freight trailers as well as specialized commodity trailers are designed to a maximum payload rating. The payload carried, however, can consist of a wide range of product densities. Insulation, for example, would be light and bulky where cartons of canned paint would be very heavy. In both these examples, the same trailer could be used. Using the total cubic capacity of a normal van trailer with a high density load, could very well overload both GVWR and GAWR. I believe that any trailer rated with a normal GVWR which is exceeded would also exceed the legal highway weight limits. Trailer manufacturers certainly have no control over an operator who decides to operate illegally.

Another popular specification used in trailers is a sliding running gear which is used by operators to distribute their loads between the axle(s) and the upper coupler assembly. By sliding the running gear forward, load is transferred from the upper coupler to the axle(s) with the opposite taking place by sliding the running gear rearward. If the operator elects to ignore using this feature to control the amount of axle load, it is certainly probable that the GAWR would be exceeded in specific cases. The trailer manufacturers have no control over this situation.

Flatbed trailers may be used for any number of commodities. A very popular use is the hauling of steel products such as plate, sheet, bar, rod, pipe, coil, etc. In the case of coil, this product is not only very dense in weight but takes little space resulting in a concentrated load rather than evenly distributed. Here again, the placement and quantity of the coil(s) loaded at the steel mill may result in overloading the stated GVWR and/or GAWR of the vehicle. The trailer manufacturer has no control over this condition.

Miller Trailers, Inc. manufacturers bulk fruit trailers for the citrus industry in Florida. If a severe freeze occurs such as happened in January 1977, the fruit must be picked and processed within several days. The Governor degrees a state of emergency and lifts all highway weight limits. This results in exceeding the GVW and GAW Ratings of the vehicles being used. The trailer manufacturer has no control over this condition.

Each of the circumstances stated above are not intended usage as far as the design and ratings of the manufacturer. They are, however, all forseeable conditions, reasonable or not, because manufacturers have seen this usage occur in the past and it will undoubtedly occur in the future. Manufacturers have no way of knowing if or when any of these conditions will occur and couldn't prevent them if they did know. It doesn't seem reasonable that a manufacturer could be charged with a safety related defect under these circumstances.

Mr. Berndt, I sincerely believe that most, if not all, trailer manufacturers make every effort to manufacture vehicles that are safe to operate on the public highways. We just can't afford not too. Possible I have misinterpreted the meaning of the legal interpretations from NHTSA on this subject.

I would appreciate hearing from you on this serious matter.

L. M. Anderson, Vice President Engineering

CC: D. VIERIMAA -- TTMA