AFFORDING REALISTIC STOPPING BEHAVIOR: A CARDINAL CHALLENGE FOR DRIVING SIMULATORS

Abstract

Drivers adopt nearly constant deceleration rates when intending to stop at a distant target. In driving simulators however we often observe different control strategies. Depending on simulator fidelity, deceleration profiles range from saw-tooths to multi-modal profiles to profiles that do resemble those seen in reality. These deviations from reality suggest that drivers have difficulty controlling their vehicle based on the assumption that a constant deceleration rate (approximately constant brake pedal depression) is most efficient at least from a control and attention point of view. The discrepancy between reality and simulation is attributed to the fact that perception of distance, speed, and acceleration, as well as time-to-collision are biased in all current driving simulators (i.e. they are perceived at scaled magnitudes). We introduce a driver model for stopping behavior and demonstrate its capability to reproduce the braking profiles observed in various driving simulators by varying only two model parameters: i) control gain, and ii) the perceived time-to-collision at which braking is initiated. For a given set of simulator dependent perceptual biases in distance, speed, and acceleration estimation, it appears that drivers only need to adapt these two parameters to achieve efficient deceleration, which in some cases takes surprisingly much practice. The reason is attributed to the fact that such a simple adaptation is perceived as counter intuitive when the perceptual biases do not satisfy a particular ratio. If for example, acceleration perception is accurate but speed and