This article puts forward the view that, for each transportation planning or management problem, there is a particular way to simultaneously define the multiple levels of procedures useful for the problem and set it in its proper perspective, the latter essentially by the identification of what...

This paper illustrates and extends our previous conceptual framework for the description of the components and interactions of transportation systems. The framework, which made use of the notions of procedure (or mapping) and steady state equilibrium, previously comprised demand, performance and...