F2008-02-009
Visual Warning Method Using Attentional Induction by Light Flashing
In these late years, the number of accidents in the traffic is increasing. The traffic conditions are extremely severe. Technology to quickly inform a driver about dangerous information has been developed to reduce cognitive mistakes that are occupied 64% of the cause of traffic accident. Recent car navigation is mainly used in warning method, however it is expected that the method is no practical use for some sudden traffic accidents, because drivers have to turn their eyes to the display.
In this work, we proposed the visual warning method by flashing LED (Light Emitting Diode) to notice the driver dangerous information quickly and precisely. We experimented on two kinds of experiments. The fundamental experiment: LED color and brightness are considered as parameters. The experiment about warning methods: we replicated sudden traffic danger on the simulator. And three warning patterns: using car navigation, LED flashing and no warning were compared. Then the easiest method to notice the traffic accidents was discussed.
The fundamental experiment: we measured the reaction time, which is difference between the LED flashing and button pushing when he notices the LED flashing. We looked for difference among reaction time that changed LED brightness: 80, 160, 285, 450 and 560cd/m2 and color: red, blue and yellow. Six subjects were tried in the darkroom as nighttime driving, and three subjects were done in the bright room, as daytime driving.
Under the same LED brightness condition and in the darkroom, red LED flashing was the hardest way to notice compared with the other colors. Under the same colored LED condition and in the darkroom, the difference of reaction time was found when the LED was changed brightness.
On the experiment of warning method, subjects simulated driving. We put the objects of human mocking on the sidewalk along the road where a subject drives. When a subject simulated driving, the human object was sprang out from the crowd. The distances from car to the position of sprang human object: 15m, 20m or 25m from right or left side.
A subject was warned when human object had started crossing the road. The warning methods are by the car navigation, the flashing LED or no warning. The car navigation indicated the direction of danger on the display with sound. The LED of direction of danger was flashing with sound. We measured the time difference between the crossing start human object and the stepping break pedal when subject notices the ones.
As the result, under the experiment conditions: distance from the car to human object is 20m or 25m from left side, subjects were not easy to notice warning by car navigation display compared with no warning. Instead, under all the conditions, it became easily to notice warning by LED compared with no warning. Comparing with no warning system case, the LED warning can be expected bigger effect compared to the car navigation warning.
Poster presentation: Man-Machine-Interaction