STATISTICALLY BASED METHODS FOR EFFICIENT SAMPLING OF INLAND WATERWAY FREIGHT CHARGES
Preliminary results of work on the estimation of freight charges for commodity movements in the Ohio River Basin are presented. The U.S. Army Corps of Engineers had rate quotations on 875 of the approximately 12,000 movements in the basin and funds to obtain an additional 325. Consad Research Corporation was engaged to apply statistically based analysis to specify the sample that would give the most accurate estimate of freight rates for the given sample size. The traffic universe and original rate quotations were stratified by commodities and annual tonnage. There were 18 commodity strata, each of which was broken down into 3 volume substrata. The original rate quotations were used to calculate the sample size required for each of the 54 cells at several levels of sampling error and confidence intervals. This indicated the additional points needed. These points were also apportioned among the strata on the basis of freight charges to achieve efficiency in estimating total system charges. Points were also allocated among the three cells of each stratum for purposes of statistical reliability. The resulting sampling plan had a projected error of 5-39 percent for each stratum and an error of 12.9 percent for the system as a whole. Mathematical relations were also derived and applied to estimate freight rates for water and alternative overland movements. The methods used should result in greater reliability in the estimation of freight charges.
- Record URL:
- Summary URL:
-
Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309031052
-
Supplemental Notes:
- Publication of this paper sponsored by Committee on State Role in Waterborne Transportation. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
-
Authors:
- Matzzie, Donald E
- Camino, M
- Syskowski, D
-
Conference:
- 59th Annual Meeting of the Transportation Research Board
- Location: Washington District of Columbia, United States
- Date: 1980-1-21 to 1980-1-25
- Publication Date: 1980
Media Info
- Media Type: Print
- Features: Tables;
- Pagination: pp 14-19
- Monograph Title: Inland Waterway Studies
-
Serial:
- Transportation Research Record
- Issue Number: 763
- Publisher: Transportation Research Board
- ISSN: 0361-1981
Subject/Index Terms
- TRT Terms: Commodities; Economics; Freight traffic; Inland waterways; Rate making; Rates; Statistical analysis; Statistics; Transportation planning
- Uncontrolled Terms: Freight rates
- Old TRIS Terms: Cargo rates; Commodity statistics; Inland waterways economics
- Subject Areas: Data and Information Technology; Economics; Freight Transportation; Highways; Marine Transportation; Society;
Filing Info
- Accession Number: 00330032
- Record Type: Publication
- ISBN: 0309031052
- Files: TRIS, TRB
- Created Date: May 21 1981 12:00AM