Abstract
It is well known that moving dots, e.g., expanding toward the eye, in a display may induce linear forward vection to the stationary observer. It is not clear, however, whether a series of real flickering lights, arranged along a road producing apparent motion, could work as vection inducing stimuli to modulate the driver's speed sensation. In this study we examined this possibility of the vection effects in a real driving scene. 3D freeway-driving movies were presented as test scenes on a hemisphere-screen of 8.5 m diameter which produced a wide visual field of 120 deg. The vection inducing stimuli consisted of the flickering poles placed on both sides of a freeway in the driving scene. These vection inducing stimuli produced apparent motion toward the driver with various speeds. Observers compared two successively-presented scenes with and no vection inducing stimuli, and chose the scene where observers had faster speed sensation. The scenes with no vection inducing stimuli served as references. The size of the poles, interval distance of the poles, and various traffic environments in the freeway were the experimental variables. Twenty five observers participated in the experiment. The results showed that the flickering poles on a road could increase consistently driver's speed sensation with the speed of apparent motion regardless of the size of the pole and traffic environments. But reducing interval distance of the poles decreased the driver's speed sensation. These findings suggest that, on a real freeway, a series of flickering poles could be a new and effective tool to control the speed of cars by changing the speed sensation of drivers.