Chapter 8: Modal Diversion

The reasons why passengers and freight operators choose one form of transport over another are many and varied. There is, however, a view that we can broadly classify the influences into those that are related to time, to cost, and to service quality (the latter being additional to time-related influences). The challenge for any investigation of influences on modal choice is to identify the attributes that describe each class of influence and to place weights on each attribute to establish its relative influence. In addition, it is recognized that not all attributes are easy to measure, and hence are often ignored in an analysis even though they continue to influence modal choice.