Chapter 29: Modelling Response to Information Systems and Other Intelligent Transport System Innovations

For the purposes of the current chapter, we will assume that intelligent transport systems (ITS) should be taken to include all those systems which use information technology to inform, monitor, control or charge the traveller or to provide him/her with travel-related services such as pre-booking which might affect his/her travel decisions. With such a broad definition, the modelling issues centre on how such systems help to define the traveller's choice set or his perception of the attributes of the options available, and how this affects his behaviour.

The impact of information systems and other ITS innovations on travel demand and transport system performance can be modelled in many different ways but the key issue for the modeller is to determine the appropriate level of aggregation. As ever, this will be determined primarily by the purpose of the exercise. At one extreme, strategic planners might welcome an aggregate model which uses information theory to predict the consequences that ITS innovations should have for the efficiency of the transport system and hence for costs and demand. At the other extreme, the designers of ITS applications would welcome a detailed representation of the extent to which modification of aspects of design or delivery might influence the behaviour of particular categories of traveller and hence affect the performance of some component of the transport system.