Interpretation ID: aiam1936
TTMA
2430 Pennsylvania Avenue
N.W.
Washington
DC 20037;
Dear Mr. Wieriman: This responds to the Truck Trailer Manufacturers Association's May 1 1975, request for a determination of what speed the National Highway Traffic Safety Administration (NHTSA) considers as 'highway speeds' in establishing gross vehicle weight ratings (GVWR) and gross axle weight ratings (GAWR) under the requirements of 49 CFR S 567.4(g)(3) and (4).; For purposes of GVWR-GAWR calculations, NHTSA will consider 'highwa speeds' to be the 60 mph value used by the United States Tire and Rim Association in assigning unqualified ratings to their tires. Therefore, trailers which are capable of speeds of 60 mph or more should be assigned ratings which reflect vehicle capabilities at 60 mph.; Sincerely, James C. Schultz, Chief Counsel