1 THE EFFECT OF LATERAL MOTION CUES DURING SIMULATED DRIVING

The vast majority of driving simulators currently in existence do not include motion systems. When motion systems are present, they are often too small to reasonably represent the forces experienced in an actual car. Nevertheless, simulators with little or no motion are routinely used to characterize driver behavior and safety. The underlying assumption is that measures of driving performance such as lane violations or heading errors are valid indicators of relative driving performance even in the absence of motion cues. Ford's Research & Advanced Engineering group operates a driving simulator called VIRTTEX (VIRtual Test Track Experiment) that has enough motion capability to realize lateral scale factors between 0.50 and 0.70 during non-emergency driving. This simulator has been used to compare both driving and vehicle performance measures during simulated driving at various levels of the lateral scale factor. Results from two experiments are presented. In the first experiment an event detection protocol was used to measure the level of distraction induced by various in-vehicle tasks such as hand-held or hands-free cellular phone operation. Forty-eight adult drivers participated in the study with the VIRTTEX motion system set to a lateral scale factor of 0.6. Six additional test participants experienced the same protocol with only vertical motion feedback. In the second experiment, 24 test participants were asked to follow closely-spaced cones while executing