Hub and spoke designs have been adopted by many air carriers and motor carriers in recent years. This paper compares rectilinear distance transportation costs for hub networks with two types of demand to investigate how well an idealized model predicts the cost for real-world demand. The...

We present an overview of continuous approximation models that have been developed for freight distribution problems. A taxonomy of six classes is used to differentiate the problems and a brief review of each paper is provided. This paper stresses important principles and key results from the...

Urban regions contain a hierarchy of roadways, ranging from a dense network of low speed local roadways to sparser networks of higher speed roadways. Because minimizing travel time is usually more important than minimizing travel distance, vehicles may detour from the route of shortest distance...

Consolidating small freight shipments into vehicle loads allows more efficient and frequent shipping by concentrating large volumes onto relatively few transportation links. This paper analyzes three schemes for routing freight shipments via consolidation terminals in an idealized many-to-many...

Time definite freight transportation carriers provide very reliable scheduled services between origin and destination terminals. They seek to reduce transportation costs through consolidation of shipments at hubs, but are restricted by the high levels of service to provide less circuitous...

This paper develops a continuous approximation model of a general freight carrier serving a fixed region with an increasing density of demand. Terminal, transportation and relocation costs are considered. As the demand for service by a freight carrier increases, transportation terminals are...