When the vehicle is moving, the speed would be affected by other vehicle in its lateral position. To explore the influence of the lateral vehicle on the speed of the moving vehicle, 30 video cases are extracted and indicators like speed, acceleration, distance are obtained. Decision tree model is used to analyze the importance of the factors which affect the speed change of the moving vehicle. The results show that lateral distance at the moment of decision-making is the most important factor. When the lateral distance is not greater than 0.77m, the speed of moving vehicle would decrease. Otherwise, the speed of the moving vehicle would increase or remain unchanged. According to the frequency distribution histogram, the speed variation of the decelerated samples and accelerated samples are both 1-3m/s. This research finds the law of the speed variation of the moving vehicle because of the influence of the lateral vehicle and contributes to new ideas for studying microscopic driving behaviors.
 

Lateral Vehicle;Driving Speed;Lateral Distance;Driving behavior