When a package is shipped by rail from one point to another, a waybill is prepared at the originating freight office. This document shows, among other things, the total freight amount of the shipment. When a less-than-carload (lcl) shipment involves more than one railroad, the revenue from the shipment is apportioned (at the end of each month) among the participating carriers. Theoretically, it would be possible to compute for each individual waybill the required divisions of the revenue, in accordance with existing rate tables, ICC regulations, agreements, routing charts, etc., but, because of the tremendous number of lcl shipments, a monthly ‘100 per cent count’ would be prohibitive from the standpoint of cost and because of the lack of trained personnel. Consequently, railroads have agreed on a ‘percentage plan’ for making lcl ‘interline settlements.’ Operations Research, ISSN 0030-364X, was published as Journal of the Operations Research Society of America from 1952 to 1955 under ISSN 0096-3984.