This paper describes the use of traffic forecast techniques. These techniques were developed and implemented in the context of the QUO VADIS project, within the OPERA expert system approach. The paper explains why traffic forecast is necessary. The paper describes how this takes place into the expert system. An example is given of an incident scenario simulation. In this example, it is shown what influence the OPERA information and guidance strategies have on travel times along some itineraries in a Scottish network. It is concluded that demand forecast still needs to be enhanced. Another conclusion is that OPERA exhibits a coherent behaviour.
Abstract