ABSTRACT

Research on human task behavior has traditionally been performed in either laboratory settings or real world environments. While a laboratory setting provides explicit control over experimental conditions, it often lacks sufficient realism. This realism is present in real world situations, but these are prone to uncontrollability and unexpected disturbances. Therefore, simulations are required that provide more realism and ecological validity, while at the same time providing excellent control (Brookhuis, Bos, Mulder, & Veltman, (2000); DiFonzo, Hantula, & Bordia, (1998); Sauer, Wastell, & Hockey, (2000); Brehmer & Dorner, (1993)). For this purpose, various simulators have been developed at the University of Groningen (Bos, Mulder, & Ouwekerk, (1999); Wolffelaar, (1996); Wolffelaar & Van Winsum, (1993)), the first one being a driving simulator. When building such a simulator, it is not only important to have a good model of the physical world. To provide a realistic environment for studying human behavior, the behavior of virtual traffic participants also needs to be simulated. The current

simulator uses simple agents for simulating other traffic (Wolffelaar, (1996); Van Winsum, (1996)). These agents are controlled by a small set of rigid rules. These rules enable the agents to function in the simulated traffic environment. However, because of their rigid rules, their behavior is very straightforward and predictable. People driving in the simulator have the impression that other cars are simple robots. Different kinds of traffic behavior and emotional influences, for example aggressive driving styles, or elderly people’s driving styles, are very hard to model. Also, new traffic situations require the agents to be partly rewritten. For realistic agents in simulators, simple rules are not enough. Tambe et al. (1995) show that the requirements for intelligent and autonomous agents in interactive simulations should be addressed by using a sophisticated cognitive model. They used the SOAR cognitive architecture (Laird, Newell, & Rosenbloom, (1987)) to successfully create realistic automated pilots for use in simulated combat exercises (Hill, Chen, Gratch, Rosenbloom, & Tambe, (1997); Jones et al., (1999)). The present paper describes a new cognitive model that can be used for simulating traffic participants. The goal of this model is to generate more realistic driving behavior, incorporating emotional aspects into this behavior, and making the agents more interactive. In the next section, the approach followed in designing this model will be explained, and the theoretical and technical background needed for this approach will be discussed. Thereafter, the model and its subsystems will be described. Finally, the paper will be completed by a look into the future.