ABSTRACT
This chapter explores the methodological foundations of a rational approach to long-range planning problems. The interdependencies of the transport system and the other elements of the environment, both in the planning and operation of these systems, influences the evolution of, and the requirements for, future environments and further aggravates the uncertainty inherent in long-range planning. The planning problems generated by uncertainty are not just academic curiosities, but perplexing aspects of every phase of the planning process; this is indeed the case for most decision-making activities. The spatial character of transport networks easily admits representation by graph-theoretic concepts. Estimation theory has traditionally been invoked as providing the needed tools for identification, adaptation, and decision-making problems. A prediction, statistical or otherwise, is valid for detailed estimates of costs and benefits over a planning period that is limited by a desired level of confidence, probabilistic or otherwise.
