Modeling Driver Behavior as a Sequential Risk-Taking Task

Acceleration models are at the core of operational driving behaviors, and include carfollowing models which capture interactions between a lead and following vehicles. The main assumption in these models is that the behavior of the following vehicle (e.g. change in acceleration) is directly related to a stimulus observed/perceived by the driver, defined relative to the lead vehicle (e.g. difference in speeds, headways etc.). An important aspect heretofore missing from previous formulations pertains to the stochastic character of the cognitive processes followed by drivers, such as perception, judgment and execution while driving. The objective of this paper is to explore and evaluate a carfollowing model that reflects the psychological and cognitive aspects of the phenomenon and captures risk taking behavior under uncertainty. In this model, Tversky and Kahneman’s Prospect Theory provides a theoretical and operational basis to weigh a driver’s different alternatives. The model is implemented and tested in order to assess its properties and those of the resulting traffic stream behavior.