MODELING DRIVERS ’ DECISION-MAKING PROCESSESES FROM ROAD SIGNS

Road signs aim at expressing a message to road users in the form of actions about objects. For one given sign, both actions and objects are well determined because legislated. However, it is well known that the road users do not respect systematically those laws. So, the issue of this contribution is why does the observed decision-making vary from the expected decision-making and why do not road signs fill their role in this process? We reasoned that a first step to study this gap between expected and observed behaviors could be comparing expert and novice drivers (whose behaviors differ on the road). A second step would be to study the device itself by building an ontology of road signs. Finally, because understanding is context-dependent, we propose to use a context-based formalism of representation called Contextual Graphs for representing and interpreting drivers ’ behaviors. KEY WORDS Road signs, procedures vs. practices, decision-making in context, contextual graphs