Effect of longer combination vehicles on the total logistic costs of truckload shippers

The purpose of the research described in this paper was to examine the effects of using longer and heavier tractor-trailer combinations from the standpoint of the individual firm or shipper rather than from the viewpoint of the motor carrier. The objective was to determine the effect of longer combination vehicles (LCVS) not only on shippers freight costs but on their inventory and other logistical costs as well. A sample of companies in selected industries provided data on their principal products, traffic flows, and logistics costs in a mail survey. These data were entered into a computer program called the Freight Transportation Analyzer (FTA) which calculated the component logistics costs associated with shipping by single trailers and by two alternative types of double trailer LCVS. A major finding of the study was that, given sufficient flows of a company`s product in a traffic lane, LCVs would in most cases greatly reduce the total logistics cost of firms that currently ship in single trailer truckload quantities. Annual lane volume, lane distance, and annual lane ton-mileage appeared to be good indicators of whether or not shipping by LCVs would benefit a company, whereas product value had surprisingly little influence on the cost-effectiveness of LCVS. An even better indicator was the ratio of current annual freight costs to current annual inventory carrying costs for a firm`s single trailer truckload shipments. Given the current trend toward maintaining small inventories and shipping in small quantities, it is not clear to what extent shippers will abandon single trailer transport to take advantage of the potential reduction in total logistics cost afforded by LCVS.