Project number: V 1014 SOME COMMENTS ON DYNAMIC TRAFFIC MODELLING lN THE PRESENCE OF ADV ANCED DRIVER INFORMATION SYSTEMS

The emergence of advanced driver information systems sets new chal-lenges in the area of traffic modelling and simulation. The use of tech-niques such as autonomous route guidance, advanced incident warning or information channels dedicated to traffic information must be incor-porated in a new generation of traffic models. This paper first discusses the impact of these new systems on modelling methodology, with an em-phasis on some important issues to make the new models both realistic and adaptable to technological and sociological evolution. The main issues are the avoidance of the "steady state", "perfect in-formation " and "uniform behaviour " assumptions commonly made in traffic simulation. The need of an explicit model for traffic information flow and of behavioural routing methods allowing for the real time use of this information are introduced as consequences of this first conclu-sion. These in turn have consequences on more technicallevels, such as network representation and traffic metaphors. The argumentation developed is then illustrated using the definition of some of the modelling concept within the P ACSIM model for traffic assignment. The dynamic nature of the simulation, the concepts of "packets " (considered as a traffic metaphor) and multi-level network, the structure of the information network (as distinct from the road network itself) and finally the bi-level behavioural routing methodology applied in P ACSIM are shown to be coherent with the requirements discussed in the first part of the paper. 965