PROGRESS REPORT OF COMMITTEE ON ECONOMICS OF MOTOR VEHICLE SIZE AND WEIGHT. II: THE FREIGHT'S THE WEIGHT

PAYLOAD WEIGHTS AND GROSS VEHICLE WEIGHTS ARE RELATED TO THE SHIPPING DENSITIES OF COMMODITIES HAULED AND TO THE CARGO VOLUME CAPACITIES OF FREIGHT VEHICLES. WITHIN THESE FACTORS LIE THE PRESSURES FOR INCREASED WEIGHT ALLOWANCES FOR LINE HAUL HIGHWAY FREIGHT SERVICE. ONE PHASE OF THE COMMITTEE'S STUDY WAS TO DETERMINE THE WEIGHT DEMAND PATTERN OF FREIGHT TRANSPORTED BY HIGHWAY. SUCH DATA PREVIOUSLY HAVE NOT BEEN AVAILABLE. THE COLLECTION OF A GREAT AMOUNT OF COMMODITY DATA IS REPORTED IN THE PAPER, INCLUDING SHIPPING DENSITIES (POUNDS PER CUBIC FOOT) OF ALL CLASSES OF FREIGHT, AND THE TONNAGES OF EACH CLASS OF COMMODITIES THAT WERE TRANSPORTED IN 1954 BY EACH OF THE FIVE MAIN MEDIA OF TRANSPORTATION IN THE UNITED STATE (RAILROAD, HIGHWAY, INLAND WATERWAY, PIPELINE, AND AIRWAY). REPORTED IN DETAIL ARE THE TONNAGES AND SHIPPING DENSITIES OF THE COMMODITIES MOVED BY LINE HAUL HIGHWAY FREIGHT. THE CHARTS OF THESE DATA INDICATE THAT A PREPONDERANCE OF THE GENERAL FREIGHT LIES IN THE RANGE OF SHIPPING DENSITIES BETWEEN 25 AND 50 PCF. FOR FLOWABLE COMMODITIES THE SHIPPING DENSITIES ARE STILL HEAVIER. APPROXIMATELY 48 PERCENT OF THE HIGHWAY FREIGHT WEIGHS LESS THAN 50 PCF, WHEREAS ONLY 9 PERCENT OF HIGHWAY FREIGHT WEIGHS LESS THAN 25 PCF. THE REPORT DISCUSSES THE IMPLICATIONS THAT ARISE WHEN A SHIPPING DENSITY OF 50 PCF IS CONSIDERED AS AN END POINT FOR THE WEIGHT OF COMMODITIES WHICH COULD BE LOADED SO AS TO VISIBLY FILL THE CARGO BODIES OF LARGE VEHICLE COMBINATIONS. USING THIS SHIPPING DENSITY WITH FREIGHT VEHICLES OF MAXIMUM DIMENSIONS ALLOWED BY THE AASHO SIZE AND WEIGHT POLICY RESULTS IN MAXIMUM GROSS VEHICLE WEIGHTS OF ABOUT 130,000 LB FOR ONE-CARGO VEHICLE COMBINATIONS AND ABOUT 180,000 LB FOR TWO-CARGO VEHICLE COMBINATIONS. /HRB/

  • Supplemental Notes:
    • Vol 37, pp 21-44, 14 FIG, 3 TAB, 17 REF
  • Authors:
    • Kent, M F
    • Feldman, E R
  • Publication Date: 1958

Media Info

  • Monograph Title: Proceedings of the Thirty-Seventh Annual Meeting of the Highway Research Board, Washington, D.C., January 6-10, 1958
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00223532
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Oct 3 1971 12:00AM