To reduce a collision accident from behind by urging a driver of a following vehicle to prepare the next brake operation by informing a state of an acceleration operation and the brake operation for the operation of the vehicle, and reducing the time difference of the brake operation between a preceding vehicle and the following vehicle.

The state of drive operation of acceleration and braking is informed of the following vehicle with marker lights having blue, yellow and red color. The blue color light is on during acceleration, the yellow color light turns on when the acceleration is released, the red color turns on when the brake is actuated, the yellow color turns on when the brake is released, and the blue color turns on when acceleration is operated.