This paper studies the possible integration of long-haul operations by transportation mode and service level (defined by guaranteed delivery time) for package delivery carriers. Specifically, we consider the allocation of deferred items to excess capacity on alternative modes in ways that allow...

This paper determines flight frequencies on an airline network with demand-supply interactions between passenger demand and flight frequencies. The model consists of two submodels, a passenger airline flight choice model and an airline flight frequency programming model. The demand-supply...

This paper examines economies of scale and density in urban rail transport. It isolates the effects of constant and non-constant returns on output and productivity growth using data relating to 17 rail systems in cities around the world. Estimates reveal constant returns to scale but increasing...

We create a formulation and a solution procedure for fleet sizing under uncertainty in future demands and operating conditions. The formulation focuses on robust optimization, using a partial moment measure of risk. This risk measure is incorporated into the expected recourse function of a...

This paper investigates the impact of a vendor managed inventory (VMI) strategy upon transportation operations in a supply chain. Specifically, the issue of batching to enable better use of transport vehicles is studied. A system dynamics methodology is used to develop difference equation models...

The scheme of a frequent flyer program describes how travelers accumulate and redeem their frequent flyer miles in the program, and determines the amount of benefits travelers can receive from the program (e.g., number of free trips). In the US, there are three basic types of frequent flyer...