Changing Driver's Sensation of Speed Applying Vection Caused by Flickering Boards Placed on Sides of Road

We propose a method for presenting visual stimuli to change a driver's sensation of speed on a freeway: utilizing vection, one of the perceptual properties needed for self-motion and show that this method can be used on a freeway with CG simulation movies. Furthermore we investigated the relationship between the velocity of vection-inducing stimuli and the sensation of speed. Our study consists of three experiments. In all experiments, the simulated freeway 3D movies were presented on a wide hemisphere screen and the magnitude of the observer's sensation of speed was measured. Vection-inducing stimuli were produced by flickering in the boards on both sides of the freeway. This flickering yielded apparent motion. We set the speed of the vection-inducing stimuli and that of the driver's car as experimental variables. The observer compared two movies consecutively presented with different conditions and selected the one that gave a sensation of faster speed. The observer's sensation of speed increased linearly with the speed of vection-inducing stimuli. Our study suggests that controlling the speed of vection-inducing stimuli could enable the driver's sensation of speed to be manipulated in real freeways.