Interpretation ID: nht75-5.4

DATE: 11/20/75

FROM: AUTHOR UNAVAILABLE; Frank A. Berndt; NHTSA

TO: Wisconsin Trailer Co. Inc.

TITLE: FMVSR INTERPRETATION

TEXT: The Federal Highway Administration's Bureau of Motor Carrier Safety has forwarded to the National Highway Traffic Safety Administration (NHTSA) your September 17, 1975, petition to establish a ruling that trailers with a gross vehicle weight rating (GVWR) of 50 tons or less are required to establish load-carrying capacity at a speed of 50 mph. Heavier trailers would be required to display signs of their maximum rated speed if less than 50 mph.

The NHTSA has already issued a ruling in this area, a copy of which is enclosed for your information. It requires that the Gross Axle Weight Rating (GAWR) and GVWR on the vehicle certification plate be calculated on the basis of the vehicle's maximum attainable speed, or 60 mph, whichever is lower.

The NHTSA is also considering rulemaking to amend the definition of GAWR in conformity with this interpretation. Your letter will be considered as a comment on this rulemaking.

Sincerely,

Enclosure

September 17, 1975

Bureau of Motor Carrier Safety -- Department of Transportation;

Attention: Robert A. Kaye -- Director

Subject: Petition for Reconsideration of 49 CFR 393.75 Tires -- (Docket MC-56)

Dear Mr. Kaye:

We have been informed by Rogers Brothers Corporation, that the Bureau of Motor Carrier Safety ruling MC-56 will become effective on October 1, 1975.

We do not have a copy of this ruling, and I therefore cannot speak for it or against it. I can only assume from the information supplied to us, that this ruling will not allow trailers to have a rated capacity based on a speed of 20 miles per hour.

We at Wisconsin Trailer Company, have for many years, advocated a capacity rating on trailers based on a travel speed of 50 miles per hour. It is our opinion that the 50 mile per hour speed rating should apply to all trailers having a rated capacity of 50 tons or less. With the advent of powerful trucks and super highways, trucks and truck-trailer combinations are moving at a high rate of speed, and I feel that the laws have to be upgraded to these modern times.

We find many trailer manufacturers promoting and selling their products based on a 20 or 30 mile per hour travel speed. This practice, we feel, must be stopped, as it is an unsafe and highly dangerous practice. Most users of these trailers will travel at speeds up to 50 miles per hour, even though the trailer is only rated at a maximum speed of 30 miles per hour. Who is there to stop him from traveling 50 miles per hour with a trailer rated at 30 miles per hour? Since there isn't a law-enforcing agency actively enforcing the "misuse of products", it then must be up to the Federal government to properly rate the vehicle at a minimum speed of 50 miles per hour. There should not be a variable speed capacity rating on trailers up to 50 tons.

We strongly urge the Bureau of Motor Carrier Safety to establish a ruling in which all trailers, up to 50 tons, would have a rated capacity based on a minimum of 50 miles per hour.

It is my opinion that large capacity trailers should be allowed to have a rated capacity at a speed of 20 miles per hour. In these instances, it should be mandatory that a large sign, plainly visible from another moving vehicle, be placed on the sides and rear of the trailer, so that if there is a violation regarding the speed of the unit when fully loaded, it will be recognized by the proper authorities.

If we can be of any further assistance to you, please feel free to call upon us.

Yours very truly,

WISCONSIN TRAILER CO., INC. -- LeRoy E. Mueller, President